Thank you for your question and for finding EmpowHER. Not being from the UK, I'm not sure the exact requirements for bariatric surgery there. I did locate this organization that may help though, check it out:
In regard to the stress incontinence, have you been treated for that? Here is information about the condition, including therapies/possible treatments: Urinary Incontinence
Finally, are you under the care of a therapist for your depression, or involved in group talk therapy? It can be very beneficial, and also in regard to your weight. It may help to get to the root of the problem, and deal with it so you can be healthy all-around with or without surgery.
What do you think?
Good luck and let us know what you find out or if you need help locating alternate resources.