My boyfriend doesn't want to have sex
My boyfriend and I have sex about once a month, and I would like to do it much more than that. Before we started having sex, being physical with oral sex was not a problem. A year later, we cuddle, sleep together, kiss, and are physically close all the time, but when it comes to sex, he's 'too tired,' or has another excuse. When I try to initiate, he pushes me away. When I got dressed once to excite him after a romantic evening, he said, "I thought we would do that tomorrow." I felt so humiliated. The only information he has ever given me is that he feels a little pressured, and can't do it under pressure and that he is self-conscience. Now, the thing that confuses me is that our relationship is otherwise very loving.
All said and done, I continually feel rejected in the bedroom, undesirable, and humiliated because I feel like I'm begging for it. I've tried to tell him this, and I don't think he understands because he only ever reassures me, and never changes anything.
I know what I should do ultimately so I'm not looking for that kind of advice, but I'd like to know why he might act like this. Any insights?