OP have you looked up or been told about IC, it's interstitial cystitis and sounds exactly like you describe. Does your bladder feel kind of itchy and swollen? Almost like someone put knives in it?
I also have tracking kidney pain but that's due to a valve that goes into my bladder that's narrow and the valves sometimes flips the wrong way. Only ever on the one side, but a very familiar feeling.
You really need an internal camera, scan check the health of your bladder, check valves and physical and visual checks. Can you get this privately find a local urologist. The NHS are shit with this condition as it's deemed chronic, it's also not even remotely painful, I was surprised it ached a bit but I travelled home from London immediately after.
The antibiotics I will guess are not the best cure.
You may need to read about diet and trigger foods, for me tomatoes flare massive, peppers and red wine. I found this out via an elimination diet and now get maybe 1-2 flares a year. I believe it's the nightshade family.
Take anti inflammatory when it goes, that helps.
I take daily anti histamines also helps massively.
I also make sure to double void, I think that's what it's called, when I wee I sit after I've finished and kind of push more out, always for me there is a bit more my brain to bladder connection is much better for this as I suspect my whole life I've never fully emptied my bladder.
If it's bad constantly then amitriptyline would be prescribed it dulls the nerve endings, it's an old antidepressant but being used for bladder and nerve pain, for me it worked but made me so so sleepy I came off it. Loved the sleep fur a while though.
I hope some part of this helps. I'm now 48 and about to start using the vaginal oestrogen as well as my HRT to keep my bladder healthy and on track.