Hi Emily,
I'm not giving any particular tips, but a few that will help you sort out yourself.
You seem to be worrying over your "problem", and what you need to do is think constructively and not worry.
When people have problems like your, they expect others opinion (this is wrong and may mislead you). You as all are individual and have specific ways which will help you improve. If I ask you to buy Primark, you definitely can't.
Stop Worrying. Dont try to imitate others as this cause problems. The way other people are due to their genetics and the environment. You didn't grow up in their environment.
So if you try to be someone else, you may be doing something completely pointless. This lead to depression, stress, constant worrying, not being happy, blaming yourself and not self-appreciating.
I'm sure, this is the case with you, 101%.
There are 5 inch 1 people who are happy, and 6 inch 2 who are not.
Your personal attributes are not a problem as there are millions of people with problems like that.
You are not disabled, homeless, deaf, dumb or anything. You are lucky.
What you need is building your own plan.
The moment you think:
"Oh my god, how can I achieve all what I want, within the time I have" sort of things, you become stressed, fatigued and everything.
Look at the girls in the above pic, see how poor they are, see the happiness.
Any person can become happy,
But the thing with your case is that you dont lack anything. What you need is CAREFUL consideration on how to achieve this and be yourself.
Any person is best and the way a person can override all others is by being themselves. When a person rises to their maximum potential, others cannot beat him/her.
Problem with people like you is that, you dont do it. You try and be others. This = failure.
Once you become yourself, you will achieve all what you want. Remember at this age, we people get nuisance into our heads. The person who do his/her studies while having a good life is happy both at present and in future. Concentrate on your studies. Do a job that is money generating and develop good qualities (while being kind and loving yourself!), you will find happiness. And money is not related to happiness! but you need to survive.
Crack on mate, do what is comfortable for you, world is waiting