Yes he is very interactive with his friends and honestly I think he just doesnt like us. We are very different personality than him. He is sensitive and reserved, we are sarcastic and outspoken. He goes to a very prestigious university (on scholarship) and I do think he can't keep up with the Joneses' financially and maybe he resents us for that? Gosh I hope not....... I am having a pity party and appreciate all the advice given here.
This post doesnt completely change my previous reply, but it does a little. If you and the rest of your family is the opposite of his personality, then there is more reason to think it is not your parenting style. It can still influence it, but I think different personalities influence it more.
If he is always surrounded by people who are type X, while he is type Y and he now can chose to get surrounded by 'his own kind', then yes, it makes sense even more that you have to take a backseat. This is on top of the normal changes people go through when going to college.
Let's say he wasn't your son, but just another adult. Would he spend more time with you then, or are you just too different? And the other way around, do you have many friends with a similar personality like your son? If he wasnt your son, would you be friends with him?
You dont have to answer that here, as it is an extremely personal question. It is something to think about.
My advice remains, do not force him, it will not help. Give him time and space. Pulling and pushing a donkey doesnt make it move.
Think about what he needs, not what you want or need, or what you want or need him to be or do. That is something you can talk about, and if the answer is that he doesnt need much contact, you have to accept that. You can be sad about it, for sure.
Also keep in mind that needs can change, what he needs now, doesnt mean it will always be like this. People change constantly.
If this is a money thing and he is comparing himself to his peers, then he might resent you now. However, if you have raised him all his life thay money isnt important, I think he will come back. If his values are fundamentally different from the Joneses, I would suspect it to be a phase. But it can take a few years for him to figure that out. And he has to do that himself