First of all, I don't think suicide would be morally required even if you did cause lots of harm to animals. I think we have a right to live. 

Second, I don't think suicide is the best way for you to help animals. I'm not sure of your exact situation, but as you get older you're likely to get more independence from your parents and community, and at that point you can stop eating animals products. At that point you'll also have the whole of your life and career ahead of you. If you dedicate your career to animal welfare, that will easily outweigh the suffering caused by you not being vegan for a few years in your teens. I don't think you should beat yourself up about not being vegan because you're forced by family and societal pressure.

You say you're not sure how you can help animals with your career, but I think STEM majors can do a lot to help animals! You could become a welfare biologist for example, helping study the experiences and welfare of animals so that we have a better idea of how to prevent suffering. Or you could work on developing vegan meat alternatives or cultured meat, eventually making it cheaper and easier for more people to become vegan. 

You can also donate money: because animal welfare improvements in agriculture affect a large number of animals, my understanding is that even with quite a small donation you can prevent a lot of suffering. So you don't have to make a large income to make a difference here. 

I hope this is helpful and your difficult situation improves soon!

Firstly, I'll echo Amber: you matter, and you have a right to live, no matter what. 

To answer the question: No, suicide is not rational in the slightest. You have many decades of life left. If, during that time, you convert just one single person to veganism, anywhere in the world, you will have cancelled out all of the meat you were forced to eat. If you want to go further, you can exert political pressure, donate money, work on meat replacement tech, etc, which all work on mass scale. 

Or consider it this way: If every animal rights advocate committed suicide, do you think that animals would be better off long-term? Of course not! It would probably make things way worse, with nobody to push back on a culture of animal exploitation. 

I agree with Amber!

I'll also point out that a lot of animal advocacy is growing in low and middle income countries, and having locally-knowlegeable staff or activists is an important part of that work. A lot of animal-focused work also needs STEM (e.g. cellular agriculture, biology.) Example: https://gfi-apac.org/#gfi-brazil

The age when you're old enough to have formed a lot of your own views but don't yet have much practical independence from your family can be so tough. For people who don't fit the mold of their local and family setting, it can feel like forever until you're able to live life more in accordance with your own views and values. But careers are long, and in a few years you'll have so many more options as far as how to live your life and how to contribute to things you care about.

Thank you so much for reaching out for support and advice on this. It sounds like such an emotionally hard situation, and I really hope things feel better soon for you.

If you’re currently feeling suicidal or feeling very down, I’d encourage contacting a suicide hotline and consider talking to a therapist if that’s an option available to you. Here’s an international list of helplines: https://www.iasp.info/resources/Crisis_Centres/ . 

It’s worth bearing in mind that the EA approach is about doing the most good you can with the resources you’ve got. As much as it sucks, you can’t do things with resources you don’t have. Freedom to choose what you eat is a resource that people have or don’t have, in much the same way as they may have/not have money or time.

 Additionally, while EAs often encourage having high altruistic standards, there are limits to this; it definitely shouldn’t mean taking your own life. As much as it sucks, sometimes the state of the world is that the reasonable or rational choice in a given situation means consuming animal products or things tested on animals - for example, vegans work very hard to avoid the consumption of animal products, but sometimes have to take medicine that isn’t vegan, and the vegan society endorses that:  

“The definition of veganism recognises that it is not always possible or practicable to avoid animal use in a non-vegan world. Sometimes, you may have no alternative to medication manufactured using animal products. Even if other medications are available, they may be less effective, have more side effects or be unsuitable for your healthcare needs. While it can be upsetting to compromise our vegan beliefs, we encourage vegans to look after their health and that of others, enabling them to be effective advocates for veganism.”

I can’t even begin to imagine how frustrated and upset you may be feeling. It sounds like such a difficult situation. I really do agree with the other commenters, though, about how much impact you might be able to have later on, once you have a bit more freedom. 

I’m not sure if this is helpful as an example - there may be many contextual things that feel too different, but just in case it’s helpful: I wasn't allowed to be vegan or vegetarian growing up but became vegan at university and have been mostly following a vegan diet since. I’ve convinced a lot of my friends to try vegan food and several of them have massively reduced their meat consumption as a result. Many others eat vegan when I’m around, even if they don’t normally. I’m not sure, but this may even be a thing you can do subtly now  - if it sounds possible in your context, you could try sometimes offering to cook something for your family or friends that happens to be vegan (eg. lentil dhal) and not emphasising the fact that it’s vegan. 

As other commentators have said, there are so many potential ways you might be able to help animals in future, especially with a STEM background, and I feel excited about a world where there are people so passionate about animals fighting for animal welfare. The best advice I can give based on my own experience is to focus on things you can control, and think about the future - figure out what you might want to work on, and figure out where you might want to try and build knowledge or skills to work on improving animal welfare once you can.