LDR way to much work?

We've been in a long distance relationship for over a year and a half ,it's been a lot of work. To give you some insight on the relationship and yes it is a long distance relationship over 2500 miles apart. Are used to fly down once A month for a week we can a half to visit him. We got an apartment and everything was fine I thought. A lot of signs of infidelity . Texting talking to other guys I even found a pair of men's underwear size medium and I haven't worn that since high school in my bedroom one time when I went there. We did talk about it and discuss the situation but he always came out with her excuse . And out of love I just chose to ignore it and except it. As the relationship developed I did leave we had an argument and I was in town I left and took my things. And we had a big blowout. We talk and text and got back together and he said now I know you were the one I want to marry he was jealous of another guy and he felt that first hand and he told me from his heart I was the one. I flew home and I didn't go down for another two months and that time I sent money to fix the house by things for the house so he could live better, we could live better when I came down in March I ended up staying for five months. We spent the next five months together every day everything was fine we did have our little arguments for everybody. I left to come home to take care of my house , and my things here. It's been one month and I've noticed that he's a little bit more distant and when he goes out he doesn't call or attacks and I have to hunt them down and track him down I'm feeling that we went back in time in our relationship . A perfectly good example is last night he went out with three of his friends girlfriends and went to the movies I had a couple drinks he forgot his phone at home when I he home he called me and text me and said apologized. That he forgot his phone. He said one of his friends that lives next-door was over and they were talking . We text a couple times back-and-forth I don't want to bother him I told him take his time I would be home ,call me when you're done.about an hour went by and he didn't call so I shot him a couple texts. He didn't answer for two more hours. And said he was OK they were having fun, is at home and safe. Two more hours went by and he said he was helping the one friend with her baby he clean the patio off and he took a shower. That was it never called or text Any more, he did tell me in one text that he was tired and the fan was going home but that was three hours ago. Maybe fall sleep? What should I do about that he never did call me. And that's just one example of many and many and what do you guys think?