Hello Hayley80. Sorry to hear about your problems. 12 weeks is still early in the healing process and some of what you describe might be the scar tissue beginning to form. However, this should all be checked out by medical staff and suitable explanations given to you about the causes and possible remedies.
With some surgeons, they think that their job is done once they have wielded the knife and the aftercare has nothing to do with them. Where this happens, the hospital staff are likely to collude with them and act as a block to communications in that direction. This is why we have stoma nurses, who are designated to deal with the aftercare and who probably know a lot more about the problems than would a surgeon who gets protected from things that go wrong - unless further surgery is required.
As Linda has pointed out; Don't be afraid to put your case to the stoma nurses and if you do not get satisfactory answers and support, then make a formal complaint and ask for a second or third opinion. If you are not up to doing this for yourself, then you can ask your local hospital/GP or health authority to put you in touch with a healthcare advocate who will speak on your behalf.
I hope this is helpful.
Best wishes
Bill