I really like him....long!

I've been speaking to a guy for a while now and we've been on 2 dates, our 3rd will be on Sunday. He asked me to be official after our first date but I said it was too fast and we should just continue to get to know each other. I can feel myself really starting to like him. The thing is, I ended a long term relationship 4 months ago due to cheating and I feel like I'll not be able to trust this guy after what's happened. He's a very flirty guy and is always liking and commenting on girls pictures (which he has every right to do, off course, considering I didnt want to make things official yet and I havent even mentioned it to him since it's not my place) but I feel like I'm not the only one he's talking to in this way. He said he can really see himself falling for me and sends cute little picture quotes about liking someone etc. He'll put these quotes on instagram afterwards and all these girls who's photos he likes and comments on will like it and it makes me feel like maybe I'm not the only one he's sending them too? It sounds so silly and childish but after what my ex did to me after 6 years together, I feel like I'm trying to pick things apart and make a big deal out of something that I maybe shouldn't be. I do really like him and when were together he gives me 100% of his attention, doesnt check his phone at all, we talk all the time but I guess I'm just feeling a little insecure. I dont want to end up hurt again. Do you think I'm just getting in my own head and making a big deal over nothing?