One month drought and counting...

My boyfriend and I haven't had sex in over a month and I cannot figure out why he won't. I have tried literally everything... EVERYTHING. I send him sexy messages while he's at work; I get all dolled up in lingerie to surprise him... nothing.
I've tried talking to him to figure out what is going on and he claims time and time again  that he's tired.
We used to have a great sex life, but now he won't even touch me. Anyone have any advice on what to do or say? 
Side note: I'm pretty stubborn and hate making the first move... I enjoy being jumped more than being the jumper so this is a pretty big step for me 😬
Thanks in advance!