New guys and second thoughts

[hartwig]

This is my first time posting so please be patient with me. I'm currently in a relationship which has lasted almost two years now, we've had our ups and downs but have worked through them as best as we can. I love my boyfriend, I do but the issue is something feels off. I think I always knew something wasn't quite right and tried to cover it up with the fact that we love each other but I can't hide it anymore. When people ask if I'd marry him, I have always said no. My best friend doesn't like him but attempts to get along with him and my sister and brother do the same. We've been having troubles communicating and he expects me to tell him everything without truly reciprocating. He does a lot of things that leave me upset yet on the other hand make me happy as well. Lately it has been hard to ignore the things he does wrong rather than right because often the scale is tipped in the negative direction. We have had a long talk about the fact that we both feel the relationship has an expiry date and have concluded to fight for it, the issue is I know he will never change his ways and he hasn't truly done so for the years we've been dating. I know he has shifted parts of his life and thoughts for me but I shouldn't want him to change as much as I do. In comes a coworker who is oddly everything that intrigues me. He is funny, a people person just like me (my boyfriend is introverted), clever and loyal. He treats women so well and in a relationship he is dedicated and caring; as I have heard and seen (he is single now). I oddly excited seeing him and knowing I'll be around him which I feel so utterly guilty about. I want to work on my current relationship but part of me knows it's over because I've changed and many other reasons but I'm afraid. I don't want to be alone and I don't want to see my boyfriend with anyone else. What if I'm wrong to throw all that time away? My coworker has made me realize that as much as I love my boyfriend, I need someone who isn't giving me joy half the time he is hurting me. I'm afraid my boyfriend honestly isn't what I need and I have pretending to myself that things are meant to be when their not. I need your guys opinion and ultimately your help; should I end the relationship? Afterwards should I pursue my coworker (I will be quitting soon as well due to other reasons)? Should I try and work on my relationship? Thank you for reading, I hope you can help.