yes, this sounds like cystitis to me too. Normally, I'd be inclined to drink cranberry juice. if not water fasting. I used to get this, in younger years, and then not for a long time...then recently got it again, really quite badly, after eating frozen garlic bread. (I think there may have been some melamine in it. You might be detoxing some toxins...)
But you might try this:
cantharis (homeopathic)
or berberis (homeopthic)
the former fits more the picture of intense burning and so on, the latter more the heavy weight or bruised feeling.
Last time I got this I took both, and finally it went.
(a day or so)
I don't personally have much faith in doctors...I'd expect Antibiotics , when I've seen simple homeoptahics work often in very short order.