<human>: My girlfriend and I have been having this problem for the past few months. I have a lot going on right now and sex is a big stress reliever for me. We used to have sex about 3+ times a week for the first few months we dated. But during the past three months we have only been having sex once every two weeks or so. 

She started a new physically demanding job last month and I understand she might not have the energy for sex, but even when she's in a good mood and seems to have energy, she pulls the "I'm too tired card" anyway. I've confronted her about it during the period when we had less sex before she started her new job, but she often got mad when I brought it up. I understand I may be beating the question like a dead horse, but we haven't had any good solutions yet. The only real resolution we've just came to is that I should masturbate when she's not in the mood. That doesn't really help the situation, if anything it makes me wish I was having sex more. 

I know about the possibilities of birth control interfering with her sex drive, but she's been on it long before we started having sex. I have no reason to believe she is cheating on me, and yes I understand the honeymoon period is over but I would expect at least some sex on a more regular basis. This may seem selfish, but I do a lot for her to be satisfied and I feel that she should reciprocate by keeping me happy in an area that is very important to me. I love her and she is very special to me, but I am definitely not satisfied.

Any advice would be much appreciated.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: My girlfriend says she is always too tired for sex and we now have it way less frequently. How can we resolve this issue?