Feeling odd while dating?

So little bit of a back story last year my ex cheated on me and came home and said he was dating another woman. I got out and of course that’s been a little over a year. I’m at the point in my life I have my dream job and I’m pretty much set. I also have two kids and I’m 25. However the guy I have been seeing and going on so many dates with I’m not sure why I want to pull away when things get serious. I’m struggling because even though I got cheated on it’s not my concern nor do I think all guys are like this. Today he leaned in for a kiss and I kind of hugged him to where he couldn’t. I’m not sure why I’m so nervous for a kiss. Like I’m ready but I also feel like maybe I don’t trust myself because I have made some bad choices in the past? Idk. I find myself going on these dates with him in which I haven’t went on one in over a year. I also find myself excited when he text me. He’s also very sweet and opens doors a true gentleman really. I just don’t understand why I pull away when things get close to serious? I get odd feelings like maybe I shouldn’t be doing this? Just such a weird thought to have I mean I’m 25?