I need advice? Should I end thing with the fiancé?

So my fiancé and I have been dating for about 11 months now, we have sex quit often but recently he hasn’t been wanting to, and today he told me that we have sex too much, and that he doesn’t want to have it all the time, but it sorta seems like he doesn’t want to have it at all, he cuddles with me, and kisses me still, and before you say he’s cheating I know for a fact that he’s not, because I’ve looked thru his phone and social media, and our phones are under my name, so I’m able to see who he calls and who calls him, I did find a suspicious number on his phone, but it turned out to be his boss I’m so glad I did t say anything to him because that was sorta embarrassing, I love my fiancé so much I just wish he would communicate with me more, speak up if he doesn’t want to have sex and I’m trying to, but he doesn’t instead he does it and he doesn’t enjoy it, frankly I’m not enjoying it as much anymore, what can I do, how can I get him back into having sex, and enjoying it, what can I do to spice our relationship up? Please help me. He is the one for me it’s just the lack of sex drive that is sorta concerning, he doesn’t even go down on me, hardly does any for play. HELP!