Extreme fluctuation in sex drive

I find myself severally less sexually active normally starting around fall and declining till about spring when it starts to pick back up, and in the times when I'm barely sexually active and do have sex it hurts or is uncomfortable even when we start I was in the mood, or I'm wet and it doesn't feel like I am during sex, or its just to uncomfortable (like my S.O. is to big) when I've been with him since the summer and it wasn't a problem then.