Husband watches porn...

I need some opinions...I'm a Christian woman; I'm against porn in marriages. My husband has been very ugly towards me lately bc I've been in alot of pain with this pregnancy to the point I haven't wanted sex at all the last 3 weeks. I've had severe lower back pain to the point I can hardly walk some days...my legs and feet swell & hurt, I'm having pelvic pain and pressure...but he says that his back hurts all the time yet he still has sex with me. So he told me that he watches porn sometimes bc he imagines it's me...and he sees nothing wrong with it. Honestly, it makes me feel very low & betrayed as a woman & as his wife. & he told me he wouldn't give it up, if I didn't give him more sex...am I in the wrong for not being okay with it?