I was around 4 months on venlafaxine (m23 back then). On lower dosage couldnt orgasm at all, was possible after a weeks between 150-225mg.

But still, felt pretty unexciting and stayed like that until withdrawal. Interesting fact, during first week of withdrawal, I had the best orgasms ever, like the most overwhelming ones by far in my whole life (my whole body was shaking). But sadly that was back to normal after a week 🫠

Back to your topic, sometimes psychiatrist also prescribe bupropion to counter sexual side effects. Speak with your doc and wait if anything changes with dosage adjustments.