Like previous posters said it will depend on your other health problems.
The NICE guidelines are that you must engage with a tier 3 Bariatric service for a period of at least 12-24 months, but a BMI around 50 this could be fast tracked to 6 months.
In that time you'd have to engage with psychiatrists (if needed) and dietitians, and aim to lose at least 5% of your body weight through changing your eating habits, portion control etc, to show a commitment to the changes needed after surgery (eating slowly, chewing thoroughly, eating bites the size of a 20p etc). You'll also have to show sufficient knowledge of the surgery, potential risks & post operative care & agree to take lifelong supplementation.
Google Dumping Syndrome as its not nice!!
Furthermore surgery can be delayed for a number of reasons - blood tests not being right, weight regain, another consultant from another specialty coming in and saying that your other health problem means you can't have it done yet etc.
But afterwards, you may be sick at most foods, you may have terrible diarrhoea.
Those are the bad bits.
But it can change your life & improve your health drastically so I would definitely pursue it.
Some cases I've seen, the patient changed their diet & started exercising to lose the 5% but then just carried on & on & didn't end up requiring the surgery!
They may also try you on Orlistat to give your weight loss a kick start.
I'd say join Bariatric forums, ask your doctor for a referral to a tier 3 weight management service, research as much as you can & see if there are any local Bariatric support groups where you can meet both pre-op & post-op patients.
Hope this helps! It's a brave step & you should be commended for wanting to change your health.