Mental block

So my boyfriend’s and I’s sex life has been rather dry over the past 2-3 months or so. He’s big into masterbating and I am not. Idk why but something changed and we just don’t have as much sex and he chooses to jerk one over having me. even if I dance for him, give him head, lay naked in bed, etc. So. Because of this craziness I’ve tried to take measures into my own hands and get comfortable with pleasing myself but I just can’t seem to do it. I feel guilty doing it for some reason and looking at porn/other guys online makes me feel like I’m doing one bad on my bf. Any tips/advice/etc for getting over that or any starter tips/tricks? I do have a small vibrating toy, haven’t gotten around to using it.