Difficulty masturbating??

Asking anonymously because Im embarrassed. Id never touched myself until I was 20. Id just never wanted to or even thought about or considered it. I met my boyfriend at 19 and he thought it was weird so encouraged me to try. I did and at times I can enjoy it, usually more so when we are apart and I share photos or go on Skype with him. But I still dont feel like it often. And living with him I never feel like it as I can just have him whenever I want. 
Thing is he loves the idea of me pleasing myself and always tries to get me to do it in front of him or gets disappointed when I say i havent in months. Since he does it daily and doesnt get why i dont want to.
When i do alone i usually watch porn and use a toy as i find fingers a really odd feeling. Like being able to feel inside distracts me too much. 
I really want to be able to do it for him but when i try i just get frustrated and theres kind of this pressure now.
Just any advice or anything would be appreciated 😕