I've been trying to write a reply to this for about an hour now and I keep deleting everything I type; probably because I feel sort of hypocritical typing this as I still do ketamine every weekend usually one or two days a week occasionally skipping a weekend and I feel that because of that I shouldn't really be posting here but then again I have a message of hope for you that I really want to share, so forgive me for being a hypocrite:
From personal experience I can tell you that your bladder can and most likely wíll get better if you quit and even when you would cut down significantly. I myself have had my bladder messed up to the point of peeing every hour or so, which would then be exceptionally painful (almost on par with the K-cramps) feeling like hot crushed glass having me nearly faint; I would even have to when traveling for more then an hour have to find descrete places to pee because holding in would be both impossible and too painful (which living in a large city and being female is actually really quite difficult); don't think anyone ever saw me but shit those are some dark dark memories. It got to the point of peeing blood serveral times too. Either way; at some point last winter I first cut down drastically to only a few lines once every two weeks; followed by a month long break on a holiday to another continent; actually just the cutting down to once every two weeks gave my bladder all the time it needed to heal; I think it was serveral weeks before I could honestly say I was 100% painfree and my bladder capacity was similair to the non-ketamine users around me; at times even a bit better. I still now have a 100% healthy bladder; almost as if I had never done ketamine and as you can read it was probably not uncomparable to what you suffer through. Also a friend of mine who does ketamine daily and has done for years has slightly more severe bladder issues then I had when it was at its worst and even he notices improvement after as little of a week of a break. It can and will heal but ONLY if you quit.
If you do that much K you are likely in near constant pain, if it isn't the bladder then it can be K-cramps, both at the same time or just one of them but either way it hurts all the time and the ketamine sometimes even seems nessicairy because it masks that constant pain making it even harder to break the cicle, but when you do it gets better in a matter of weeks; first improvement often being there in a few days and for me it took less then a month to have my bladder back to normal; can't say it'll be thát short for you, maybe it will maybe shorter maybe longer, but the realisation for me 'wow, I am sober and I do not have any pain :D' was really, really meaningful; most likely you may have also forgotten what it is like to live pain free and is it worth quitting the K; its such a relief and freedom to once again have a fully normally functional human body.
(I myself by the way have used ketamine for four years now; starting off about once or twice a month and a gram would last me months, after around two years that went up to a gram lasting only one month instead of serveral only a few months later I was up to around one gram a day using somewhere in between weekly and daily; fast forward one year later I was doing 3-5 grams a day at some point daily for about a month (which ended with peeing blood and a hospital visit and such unpleasantness), after which I cut back down to 3-4 days a week of doing too much ketamine, later that year there was another binge of serveral week of nearly daily which made the bladder issues return but after that the almost break and later one month break which was this past januari-februari; after that break I've been doing ketamine on the weekends but I do skip a weekend occasionally; which leads me back to feeling hypocritical typing this but for myself this is how I want my life, and as long as my bladder stays 100% healthy and tolerance does not go up I'm ok with what I do; I just wanted to add this to give perspective in what I was using, which since 2011 has been 1-5 grams a day on days that I would do ketamine, which was more often then not in terms of after even all that how fast my bladder healed, just to say that it gets better)
I wish you strength in your battle against ketamine addiction; I know how hard it is but it can and will get better; best is quitting intirely; especially if for you the compulsion is such that you cannot keep a moderate level of usage (I'm still not where I want to be, ideally I'd do it maybe twice a month just one night, but I'm working towards that) then it is better to quit completely because even though the bladder can and most likely will make a full recovery; you don't want to risk it getting to a point where it won't (which unforunately also exists).