Why cant i climax anymore????

I used to have the best orgasms with my boyfriend of almost 1 year, but the last 3 times we've had, I couldn't climax well. It was like I missed it... the last 3rd time we had sex was after a month or maybe less because my libido was so damn low. I did not feel anything sexual for some reason when we used to do it once a week at least. I usually touch my clit during PIV but idk whats wrong and I feel bad for my bf since he thinks its his fault when its not... whats going on????? Thanks for any feedback!!!