Why doesn't my boyfriend want me? ?

I am 20 and my boyfriend of 3 years is 30. We had an amazing life, he was living with me and didn't have a job. Are life started to lack pion after the first year, He said he just wasn't interested in it. I figured He had things on his mind or was feeling un "manly"... So now we have a house together he has a Job he loves, has a new truck, I'd say we are doing well but we haven't had in over a year. He honestly doesn't want much to do with me at all. Only says ily if I say it first. Gives me a quick peak befor he leaves. I talk to him and he gets defensive says stuff like " I have goals I'm tryin to reach and I'm working hard so I can enjoy life with you later, it's not all about sex and you don't always get what you want". I beg for sex, and he gets mad I want it all the time. I'm 20 I'm horny and sexy and he doesnt want me at all. I know he isn't cheating and the love is deff there but what can I do. I need the pion.. And well sex occasionally.