Hi there and thanks for sharing your current experiences on these forums with us!
It sounds like you're going through a lot of stress at the moment and especially being about to enter your last year of high school. To be honest with you, what you described sounds a lot like how I was when I was your age.
With your brother being more academically inclined than you, it's just something that you have to accept. It doesn't make you any less of a person or less valuable, some people just excel in different areas of their life than others.
With your weight struggles, just take things slowly. You sound like you know what's healthy for you, being active in sports before and everything. Maybe just try switching to healthier snacks like nuts and fruit and maybe try to get outdoors and do something active everyday to help get your mojo back.
With you not really connecting with others socially, that's totally normal, especially in high school. Well, that's me speaking from my experience only. One thing that you need to remember is that after high school, there are so much opportunities and the world is much more bigger than the little bubble of high school. It's normal to grow and change, both with our priorities and with who we are as people and as these changes happen, sometimes what we want in relationships and friendships doesn't meet the bar in terms of social satisfaction.
Just have the confidence to know that you will meet people who are more on your level and on a similar wavelength as you and remember that you are not obliged to do anything that you don't want to do. I would encourage you to still be nice and civil with people, as you never know when these people might come back into your life or cross paths with you again but just take it easy and work on being happy with yourself because when you are happy with yourself and who you are, that's what makes you magnetic and you will draw people into your life who like you for being you.
Hope I've helped you in some way
Gabby xx
