Yes, you absolutely should communicate your feelings and needs in a relationship, and that means talking about sex, too. What is stopping you from bringing it up with her? Try doing it at a neutral time when you are both relaxed, and use calm language. Use "I feel" statements and language that does not come across as judgmental or accusatory. Try saying something along the lines of, "I've noticed that our sex life has declined a bit. I feel closer to you when we have sex and I enjoy being with you, and I'd like for us to get back to a place where we are excited to have sex. What are your thoughts on that?" and then really listen to what she has to say. The medication absolutely could be a huge factor, as low sex drive is a common side effect of many medications. But the only way for you to get past this is to talk to her about it. Once you open the gates to the discussion, it becomes a lot easier to talk about it.
"Caring is not an advantage."