Since last february, there has been this feeling as if there's something either stuck or irritating my urethra. since february (of 2022), i have had over 16 urinalysis done, seen a specialist, and had my blood taken. all results came back negative?

Possible causes might be: Chronic Pelvic Pain Syndrome, Urethral Stricture. Rare causes may include interstitial cystitis or bladder dysfunction. A second opinion from a specialist can repeat the history, exam, do urine tests other than urinalysis, imaging like ultrasound or endoscopy to find that source of irritation- and ultimately help to try and relieve that discomfort.

You did not mention what specialist you saw and what tests were done. If you saw a urologist and he/she looked inside the urethra and did not find an abnormality then there is nothing seriously wrong. If not you need to do that. In the meantime drink water and avoid holding your urine for too long. Hope you feel better