Should I move on with a new beau, or try yet again to work it out with my (ex) BF of almost 2 years?

My BF and I have been on and off for 2 years. I know he loves me, but lately I realized it might not be going anywhere (like marriage). And he admitted to having doubts, doesn’t feel like he can trust “us” to make it, and was scared, etc. So we haven’t seen each other in a couple weeks.

I felt that maybe I should just try (as hard as it would be) to move on. So I went out with this guy I’ve known for about a year and we hit it off and ended up kissing and had a great time! We spent 2 days together and did the hold hands walking down the street thing, etc. and he seems very interested and I really like him. He’s adorable! Not to mention funny, kind, is happy with his career and is as much a dog lover as I am (which my ex is not).

But I’m worried that if I move on with the new guy, that it won’t work out (he lives 4 hours away), and possibly miss my ex (obviously we have some good things going on for us as well…).

The day after I get back from this great time with new-man, my ex tells me that he has thought about it and is ready for the commitment and doesn’t want to lose me. Is my ex grasping at straws, saying anything just to keep me?

So, I’m confused. Do I get back with him and try again to work this out? Or do I cut my losses and take a huge chance with the new guy?
Help? Thanks!