He only wants sex.

I've been dating this guy just over a year and when we first started dating he was always so nice and when we had sex it was when and how I wanted it. And He made me feel so happy and loved. 
Now he still makes me feel loved but when it comes to sex he will beg and beg for it. Not ever forcing me, but begging all the time.like we're cuddling and he tries to finger me. I'll come over and he'll open his door and be Reasy to sex it up.  And he gets angry if we don't have sex in a while. 
Our relationship used to be so nice when it came to making love now it just isn't. 
Any advice?