It seems you feel the experience gave you a lot of joy, so you yern to continue that joy by staying in the relationship in the hopes that the honeymoon phase shows up.
The most important thing in a relationship is open communication, have you discussed this with him in a calm and serious level? Have you told him you felt ignored? Have you told him the flirting gets to you a lot and you wish to reconsider the rules? (In a calm and formal environment) Open communication is SO important in a relationship, I can't stress how many problems can be solved by simply informing the other party and being completely honest. A lot of the time when an SO mistreats (in a non-abusive way) someone, it's usually because they don't realize the affect of their actions. So please, if you haven't already, tell him how you feel, it's not intruding and you have complete right to do this.
You need to tell him everything, how you feel you don't have enough friends and how you really want to spend time with him. Though, at the same time, it's definitely important not to have him as your ONLY link to social interaction, because yeah he has a life too, he should give you attention but he can't give you attention the entire time, so it's important to also get to know your co-workers and meet some friends, people you can hang out with that aren't your boyfriend. It's important he knows you feel ignored and you should discuss with him ways in which you can solve that issue, one of the ways you should discuss is asking him to help you find more friends around the area, maybe he knows some people you might like? Another one is possibly making a schedule so he can set some time aside every night (or few nights) to spend with you (maybe even something like a date-night). Who knows, it's important to work through these problems together.
I wouldn't break up with him unless you've tried these things consistently and haven't gotten anywhere. If you've already tried these things and have had no response, then I don't believe the relationship will work out. But by the sounds of it this hasn't been done much, so I DEFINITELY recommend trying this out before considering breaking up with him. A lot of problems can be solved by simply talking it out and coming up with a plan to tackle it.