My AST is 49, my ALT is 83, bun/creatinine is 16.3. I have right flank and back pain on right side and my UA was positive for moderate bacteria. UTI??

UTI + liver disease. You didn't mention painful frequent urination w/urgency, which are hallmarks of urinary tract infections (UTIs), whether simple cystitis (bladder) or pyelonephritis (kidney). Regardless, urine should be sent for culture & sensitivity so that doctor can confirm you've received appropriate antibiotic. Also need to monitor liver function given elevated AST & ALT, even test for infectious hepatitis.