How old are you?
Oxalate crystals in the urine indicate that you are excreting larger amounts of oxalate than is normal (hyperoxaluria) or your urine is really concentrated.
Individuals with higher levels of oxalate in urine are predisposed to developing kidney stones made of calcium oxalate.
Though no stones may have been seen, their passing could have been the reason for the trauma to your urethra and the subsequent strictures (narrowing that needed dilatation).
Blood in urine is again an indication of kidney stones. The part of the tract from which the blood is originating can be determined based on what part of urination the blood appears in your urine - at the beginning, throughout, or at the end..
If you are over 50 and pre-, post- or perimenopausal, the irritation and painful sex could be related to a drying up of the mucosa in the "female area", due to a decrease in female hormones.
This can be treated with lubricating agents or hormone medications to get you through the tough part.
Meanwhile (until the cause of the blood is determined), you can do the following:
Drink plenty of fluids, in excess of 2000 ml per day.
Take natural sources of vitamin C-rich foods, such as cranberry and citrus juices.
Increase natural calcium intake (milk products, seafood)
Add cod liver oil capsules (DHA source) to your diet.
Do write back with the details required for a more precise response.