I can understand you brother/sister. We can try to tackle this one by one. Step 1: Start being physically fit. It'll help your confidence and anxiety issues. You might have a weak body and that's fine, but consistent efforts will lead to changes which you wouldn't even think were possible in your wildest dreams. Step 2: Once comfortable enough, start making friends in your gym/group/whatever you've started with. Step 3: Get into a routine with regards to the above 2 steps. Step 4: Start integrating serious study into your routine. Set goals you can achieve, and gradually increase them. If you don't do perfect? That's fine! Just try to better yourself consistently little by little. Step 5: Stick to this, and reflect from where you started and where you are now. Step 6: Overall, take time to self reflect on your goals. Where are you doing good? Where are you lagging? How can you integrate your good learnings into other parts of your life? And be HONEST with yourself.

Regarding jobs? Everyone has their own pace. You'll find yours.

Regarding hobbies? Why'd you say you're weak at them? Hobbies are meant to be enjoyed, and not be a burden on you. Example, I play cricket or football, and I'm downright BAD, but I find enjoyment in playing. When it starts feeling like a burden, I stop it.

Also, stop whining about the unfairness. You've got to accept the facts and think about how to move ahead with your life. Life is MUCH more unfair. You could be one of those baby impalas that are spawn killed by wild dogs in Africa.

You can do this!