No Sexy Time

So my bf and I usually have an active sex life to where it's multiple times a day but lately there has been no sex and I don't know why ugh! I have tried new things and done stuff to turn him on still nothing...yesterday laid on top of him naked and gave him a little foreplay if you know what I mean but instead of it going the way I thought he started a fight with me over what happened last weekend...immediately my girl brain goes to cheating but that's just a feeling but in dire need of help what do I do?