I agree with others that there are red flags about the relationship.
A toy might give you orgasms, but it’s not going to fix the relationship.
In fact, I think a toy might make things worse by allowing the relief of one symptom without doing anything to address the underlying problem.
Just came across this thread. OMG do you have issues with your partner!
One thing that a lot of replies ignore is that sometimes a relationship works on just about every level, but there are problems in one area. In your case it’s sex, which is pretty important!
Maybe everyone is right and you should leave him, but if everything else is right in the relationship maybe it’s worth persevering?
If his preferred positions are either from behind or reverse cowgirl, then you have full access to your clit. Have you tried a Womaniser? There are loads of versions to choose from, the smaller ones are better for use with a partner. I love using it when combined with vaginal penetration.
If that works for you and makes you climax, maybe he’ll be more open to different positions so he can see you cum. It’s a big part of sex, seeing the pleasure on your partner’s face!