Do I go back to him?

I broke up with my boyfriend of four months yesterday for a few reasons. My friends had been pushing me to do it for the past month some of them even giving me silent treatment till I complied. While there were things that weren’t perfect in our relationship I can’t help but feel the decision was rash on my end. I was starting to get fed up with his emotional maturity, his behaviour would often remind me of a 12 year old. We’re also on very different paths in life I started uni this year doing a degree in Natural Sciences at Cambridge, he on the other hand does not have an English GCSE yet (we’re 19 and 18 btw) and has no set plan on what he’s gonna do with his future mainly because having no English GCSE is quite a handicap. Throughout our relationship people would always tell him he was punching massively and while at first I tried to ignore the comments, I have laterally realised he isn’t the most physically attractive and it was never the looks that brought us together for me. He also acts up around other people whether it be my friends or his friends (e.g. he’ll withdraw affection, be rude, and act off) this has led to a bit of embarrassment when people in my life meet him. So while I have just listed all this negative you must think the obvious answer is to remain broken up; however since calling him last night to break up, we sat on the phone for about an hour chatting like we usually do and when he left to go to bed my heart shattered, it hit me like a ton of bricks, I keep feeling immense regret but then when I go to message him I can’t bring myself to rekindle things. My best friend is also telling me absolutely not too and this feeling will pass and that I’ve made the right choice. But I don’t know. I feel like it’s not fair to him if I feel all this but I can’t help but want to get back with him. But am I just messing him around? What do you guys think should I get back with him?