I haven't read the rest of the replies, because I read the OP when there were only one or two, and couldn't think what to say. But I've been thinking about this all evening so I wanted to post anyway.
I'm 22 and a single parent to a 2 year old, so in sort of a similar situation. It is hard. It must be hard at any age, but I find it really, really hard to do everything. Sometimes I think I'm not doing well enough for him. There are days that I think if I had someone there, who I trusted 100% to look after him, and I had the option to just leave him and go off and live the life of a normal 22 year old, I would take it in a flash. Usually it's when I speak to friends who have been to uni, or see things that my bf is planning to do, like go on holiday with friends, or have an all night party, or if I just walk through town at 6pm on a Friday night and feeling the start of that going out atmosphere. I'm a part time student at uni and while I love it, I sometimes wish that I could do it properly, not have to worry about DS, be like the other students.
But then if I ever stop to think about it practically, I wouldn't - I don't have the option, but if I did - I wouldn't just be able to relax and enjoy a happy carefree 22 year old existence, I'd be constantly thinking about DS, wondering if I did the right thing, wondering if he was happy. Maybe I'd forget for a bit, but can you imagine being on a night out and suddenly wishing you'd been there that night to tuck them in or read them a bedtime story? Or coming back after a trip away, and suddenly he's changed and he can read or he has developed an obsession with dinosaurs or he can ride a bike, and you missed that?
Yes, sometimes I feel bad that I can't do the things I want to do. Sometimes I wish that I'd had him when I was older, sometimes I even resent him, often I feel guilty about this, and about the way I'm not perfect with him - but that doesn't even compare to how awful I imagine it would feel to know I had given him up - and this is just imagining, so I'm guessing it would feel even worse in reality. When I put it that way... it just seems like a no-brainer. Maybe it's selfish to think in terms of guilt/regrets for yourself, but I don't know.
Practically - you can do uni where you are - you can do a part time course, or an Open University course. Travelling I've pretty much accepted will have to happen once he's grown up and left home, if it happens at all. TBH even if I didn't have DS to think of, I couldn't afford to go travelling anyway, so again, not an option.