So just some ideas....bare with me.
Vaginas don’t really get loose unless you’re saying you had an episiotomy? Is this what you mean by loose?
Have you only ever had vaginal orgasms?
If you don’t like vibrators have you tried dildos or searched for other sex toys that may interest you....as well as your partner....there’s an ocean of them!

Most women do not have vaginal orgasms during sex. A very high percent. So what type of orgasm were you having before? Clitoral, body, vaginal, backside??

Why do you go into another room to masturbate? This is becoming a blackout area of communication & a wall is being formed over this issue. There’s hiding going on. Why don’t you stay in the room & show him how you masturbate? Maybe let him watch so he can see your breathing pattern, body language & movement which are key to understanding a female without the constant need for questions which can dampen the mood.

If you’ve already guided him....do it again. Try ‘edging’, where you reach a masturbating plateau & not let yourself orgasm. Then you start again. Show him how to do this which helps you build up your orgasm. It can be done for him too.

I’d also check the meds again. Even if you can orgasm it doesn’t mean that a med is not causing a side effect here hormonally or with your libido. MH drugs are notorious for that.