Thanks for your query.
As you mentioned you have gone through spinal surgery
and had urinary catheter inserted. Both conditions have led you prone to urinary tract infection
It usually presents with difficulty/pain/burning during urination, mild fever, frequency, feeling incomplete emptying, nausea
Continue taking large amount of water and cranberries.
Visit your doctor and perform tests like CBC, urinary analysis and urine culture to trace exact bug and infection. It can successfully be treated with antibiotics.
Hope it helps.