You can not change what has happened in your past, and to spend time wishing it were different, is a pointless and dare i say stupid exercise.
If you cant change it, which you cant, you might find it easier to accept that you went to university with many issues that needed addressing ( as i might say we all would have done ) .....had you not had the, albeit sometimes questionable support of your boyfriend, you might very well have coped better, but you might actually have had more problems and not coped.
The issues would have been yours to deal with and would have still gone with you, whether you had gone to university, got a job, back packed round the world or sat at home crying over silly love songs !!
the issues would not have not been there just because you had a "better" or "nicer" boyfriend. You can not run away from them and the sooner you clear them, the sooner you will be the content, happy person you crave to be.
whether that is with or without him only you can know, and no action you take is right or wrong, it merely means you will deal with your issues differently depending on the life you make for yourself - with him, he will give you support but want you tto himself for cuddles, without him you would be able to go out and make more friends ( which might challenge you !!) but you wouldnt have the 1-2-1 support he was able to offer. I hope you see what im trying to get over ????
only you can make you happy, only you can make you sad.............. i dont regret one single thing in my life ( although i am quite embarassed about some of them, but thats another story !) but i know had i not had issues i might well have been happier.............but hey !! i wasnt, i couldnt be ............but im going to bloody well try to be in the future !!!
good luck !!!