My exboyfriend and I started talking again but its not the same. I get this vibe that he's not into me aymore.?

My exboyfriend and I have been on and off for about 3 years. This last time we broke up was because I ended things because I saw his car parked outside his exgirlfriends house. She's a threat to me because they have a longer history together.Anywho, about 3 weeks after we had broken up I find out he was already dating a new girl he had met 3 weeks ago as well. (Jerk!) Well I was devasted I love this guy so much it is ridicolous. He means the world to me and I felt even worst that when I ended things he really didnt even try to get me back. & Im guessing it was because of the new girl he had just met. Well 2 months past by and everyday I hoped & prayed he called me trying to make up. About a week ago I get a text from him with an inside joke we have between us. I responded of course and was extremely happy. But I kept wondering if he was still talking to the girl he had met, but I didnt want to ask him I felt like it was too soon. So I ended up going over his house about 3 days later after he textme. He was so happy to see me, the way he was being with me was as if he missed me so much he was being soaffectionate with me. He kept kissing me & hugging me and just kept wanting to hold me through the whole time I was there. We ended up messing around that night, even though I had told myself I wouldn't. But I was so happy to be with him I didnt regret it. and was not like this was the first time we would have makeup sex that soon. I mean its been 3 years so its different. Plus, everytime we would makeup & get back together things would go back to how they were like if we had never broken up or even been apart & stopped talking. That was just us & loved it. But this time everything is different. I havent seen him since the time i was over. He doesnt even call me he just sends me text messages and only like once a day and when i reply back he wont even reply back again. When he was the kind of guy that would be calling several times a day & would want me over all the time. So i then started thinking the other girl might probably be around, but I found out today that she is not anymore. I feel stupid becayse that mean he only called me because things ended between them & not so much because he missed me. He acts like he doesnt want me around & i dont understand. & what makes me feel worst is that we've been together on & off for 3 years and this girl & him only dated for 2 months and she got to him so much he's lost feelings for me (thats what it seems like) and is now all caught up on this new girl. How can that be, he just met her & we have a history together. Im so sad he is so different with me put it this way he rather be at home all day & not do anthing than to invite me over and/or go out somewhere together. I feel pathetic that this girl of 2 months has more power over him than what I do now and we've known each other way longer. what can i do to get things back to how we were and make her forget about her. This is so devastating.I dont feel good enough anymore & feel like something is wrong with me because of this girl. I dont hate her cus its not her fault & im sure she doesnt know about me but I dont want to loose him even more.& why did he call me in the first place trying to make up if he doesnt even want me around. How can he play with my feelings knowing how i feelabout him especially since im not just any girl we shared a relationship for years. I dont know what to do. but im going crazy thinking about it and im so depress cant seem to believe this is happening. Please help me I want him to want me again.