When should you give up?

To start, I'm 23. I'm an RN. I'm living with my boyfriend at his house. We're ten months into our relationship and I'm having second thoughts. We've been friends for years. We decided to give it a try ten months ago and I found I was romantically attracted to him (which I never knew until I kissed him!) it didn't occur to me how different we are until we got about six months into our relationship. Just for reference, my longest relationship has been 3.5 years. I've had another for 1 year. And then a few for a few months or so. It seems like no matter who in with, I'm always focusing on everything that is... wrong. People tell me I haven't found my person yet. Idk if this is actually true, or if it's me who is the problem. Out of all of these relationships, only one of them has actually done anything wrong (cheat). The rest were too many arguments or personality clashes and now I'm having that SAME problem again. We are just so different, all the way down to the root. Different political views, different religious views, different interests. I wonder why the hell we are even together, all of the time. Yet I still love him and try to find ways to make us fit together. It just sucks. I'm not sure what to do. :(