Painful sex... please help

Hi guys! I'm 18 years old. My boyfriend and I have been sexually active for about 4 months now. Two weeks ago I received blood work and my second gardasil shot. I also just got diagnosed with rheumatoid arthritis and sjogrens disease. The past week when my boyfriend and I have tried to have sex I have to have him stop because it hurts so bad!! Could it be from the gardasil shot??? Could it be from the sjogrens?? Symptoms of that do include vaginal dryness... but even when we're ready to have sex I'm very wet. I'm not on medication for the RA yet but I'm not sure if that could be why. Is it possible he's doing something different??? I'm honestly so confused and just want some opinions...

Thanks!❤️❤️❤️