Any ideas for a sex life that has reached a plateau?

I have been in a long-term, committed relationship with my partner/girlfriend for almost 15 years and within the last 6 months (mostly due to her school schedule), we have not made love very often. My sex drive is SUPER high, but I've had to tone it down considerably out of respect and empathy for her limited time and energy. Since the semester has ended almost a month ago, we still haven't made love and I've been waiting ever-so-patiently, but I'm not sure if I can hold out any longer. I'm a very sexual person and love my partner to pieces, but since reaching this plateau, I can't help but to desire her even more and would like some ideas of how we could get our groove back before the next semester begins again in August. Any serious suggestions would be greatly appreciated. Thanks!!!