Diagnosis laparoscopy, removal of uterine septum and an endometrial ablation

[sweetassugarhardasnails]

I've been booked in to have all three done in one operation, please be honest how much pain am I going to be in afterwards?

You shouldn't be in any pain afterwards. Any experienced anaesthetist knows the average levels of pain killers required for an operation of this kind and will prescribe accordingly. If you need more, ask for more. There is absolutely no reason a patient should suffer post operatively.
The same goes for sickness. Gynae surgery is associated with high levels of post operative nausea and vomiting so you will prescribed a lot of anti sickness medication. If you need it, tell them. Don't suffer in silence.

Thanks