My wanted space and now i think ive lost interest.

Ok so here is the deal. Ive been with my boyfriend for almost six months. At the beginning of our relationship, he was so into me. Always texting and calling me and he was always down for whatever i had planned for us. Now he never wants to spend time with me or make time for me. So we argued a lot because of that. We use to always work out our arguements and made sure we never went to sleep mad at one another, but now he really doesnt care.Before he started the job hes at now he told me his schedule would be busy sometimes but that he would always make time for me so that we can work out. Well lately he was acting really weird. He wanted to spend more time with his cousins and never with me changed the way he talked to me and a lot more stuff. So i figured ok well we used to spend alot of time together so ill just give him his space. Also my phone has this thing that tells me when he's on the phone with someone else and now everytime i call him he's been on the phone. Another thing is he used to have 1 hr lunches and now supposedly he only has thirty mins now, so he calls me for 30 mins. But one day he told me he was going to lunch at 12:30 so i ended up calling him instead at 12:15. My phone let me know that he had been talking on the phone. This has happened at least 5 times. Well to make a long story short ive had many talks with him about how he's been acting strange but every time he gets irritated. I would cry for hours at a time and wonder what was going on. He said he would try to make more time for me but he really hasnt made any changes. So just recently im fed up of crying and trying to get him to spend time. Ive started a new job that pays a lot so now im constantly hanging out and shopping with my aunt and she's very young so shes more like a sister to me. Im 20 shes 27. We get our nails done, shop like crazy and party. Ive noticed now that im not so focused on him or texting and calling him anymore. Now i just want to hang out with my aunt. So i guess he's noticed the change in me bc now i let him txt me first or call me first. So now he's being super nice and texting me more often, being a lot sweeter and getting jealous if im somewhere. Like yesterday i told him i left work but in the mean time i ran errands so i txt him later and told him i was home and he txt me "why r u just making it home huh?" Its nice and all bc i see he cares but i feel like he took to long to make the change. Usually im always letting him know when i make it somewhere but today i just forgot and didnt really care about telling him i made it to work, and he called but i missed his call so he txt me saying " i guess u made it to work" meaning he's upset bc i didnt let him know. It just doesnt excite me now that he's doing what i wanted. I think maybe i lost interest in him bc now i just want to hang out with my aunt and party and drink. What should i do?