I’m sorry that you feel so alone. I wish I could make you feel better but without being rude, I think you already know what situation you are in and you don’t need someone else to tell you something you already know.
How long have you been together and at the start did you partake with each other? The fact he tries to hide it shows he knows it’s an issue, sorry I cannot alleviate your worries, but please don’t feel lonely, here if you need to talk x