After i urinate i feel like my bladder feels irritated, inflamed. no burning while urinating, no fever. what can cause this?

Infection? OAB?: The wording of your question suggests you know that urinary tract infection (UTI) usually causes burning when urinating. But not always, and feelings like yours could be due to a UTI. Or maybe you're developing overactive bladder (OAB), especially if you're having urinary urgency or leakage when you feel the urge to void. You should see a doctor, who probably will start by recommending urinalysis.