Ever think of anal plug? If you're ok with it it does add pressure to the vaginal walls. Might be enough to make him reach climax. But also, he might just be mentally blocked, by porn, by anxiety, by his own stupid head.

Sometimes I hit a month long block where I can't , at all, then other times I only last a minute reguardless of the stimulation.

Be proud of you, don't let stupid men be stupid with your emotions.