I don't plan on ever going to uni, but what I do know is that the majority of overweight people (outside of uni and in my experience) get by in their group of friends by making fun of themselves for being overweight - this way they beat people to it so don't suffer as badly.
Don't do this, self-deprecation is never a good look.
I'm not going to tell you you're 'fine just the way you are', because you're not. Being ~350lbs is unhealthy as it is, and it won't be improved given all the drinking and poor eating habits you my take part in like many students before you have and will continue to for years to come.
I would definitely say lose the weight, especially if it's something that could potentially stop you fitting in - it may not, but that's a) unlikely and b) still something that bothers you. Not being overweight = better health, mood, confidence and less having to worry about fitting in.
Be that as it may, the ball's in your court.