Need some advice

(This is long and I rambled a bit) I'm 20 and he is 28. I am a junior in college and he works a full time job and still lives at his parents house (he pretty much lives there by himself because his parents have two houses). We met in June and I stopped talking to him for a bit just so I can think about the age difference and see what I wanted. I decided if I wanted to give it a try and he came to see me for the day (we do not live in the same state). Since then we have been taking turns traveling to each other. The distance isn't too bad and we usually don't go more than two weeks without seeing each other. But I'm just hurt because he had the week off and I only saw him the Saturday before Christmas. He had a business trip which seemed sketchy to me because he got there at night and was home the next evening. He sent me a picture of his new hair cut at his hotel but I don't know my gut feeling is going off. I really like him and he mentioned that wherever I decide to move after I graduate college he said he will still be here. But lately my gut is really trying to tell me something. He went on a trip Friday to Saturday with his friend and told me he was there. But he got back Saturday late and then I had to cancel our plans because he didn't think twice about if I had work in the morning or to let me know a set time in the first place. We talked on the phone and he apologized and said he was going to be better and that he doesn't want me feeling unappreciated. He said he will change and make it up to me this week. We both traveled for New Years and he suggested we hang out on the 1st (today). We've talked all day but he didn't make a plan. Honestly I want to break it off. I don't know if I'm scared, or overreacting. I just want some advice. Thanks :)