Complications

This is very hard for me to say. But I went to the gynecologist for help because I am unable to get wet while having intercourse. I enjoy sex with my boyfriend of three years but for the past year I am unable to get aroused/ cum. My doctor says it's normal but was wondering if anyone else has this problem. I feel bad because my boyfriend tries everything to get me wet and I can't. My doctor told me to use lube but I feel bad.. It's just odd to me because before I was able to get aroused/wet and now I can't.