SMA PLT MAKES WRONG SIDE DOWNWIND THEN CUTS ANOTHER ACFT OUT ON FINAL APCH.

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I HAD BEEN TO THE ARPT AS A PAX FOR THE FIRST TIME 2 WKS PRIOR. I THOUGHT I COULD APCH BY DEAD RECKONING AS A PLT. UPON DSCNT OVER THE MOUNTAINS; MY PAX BECAME NAUSEATED. (HE HAD EATEN TOO SOON BEFORE FLYING). THIS CAUSED A DISRUPTION OF MY THINKING IN THE COCKPIT. I MISTOOK THE PENITENTIARY BUILDINGS AND PARKING LOT FOR THE AIR FIELD. I CALLED FOR TWR AND RECALLED WHEN ENTERING THE 'PATTERN' FOR THE INCORRECT AIR STRIP. ON BASE; I REALIZED THE ERROR AND NOTIFIED THE TWR OF THE ERROR. THE TWR REQUESTED I RECONTACT ON DOWNWIND FOR RWY 24. MY PAX CONTINUED TO BE NAUSEATED AND UPON SEEING THE RWY I SET MYSELF UP FOR DOWNWIND FOR RWY 9. AFTER NOTIFYING THE TWR I WAS ON DOWNWIND FOR RWY 24; I REALIZED I WAS ON DOWNWIND FOR RWY 9. I CROSSED THE RWY AT MIDFIELD (PATTERN ALT) AND SET UP FOR R TFC FOR RWY 24. (THE TWR HAD APPROVED ME FOR L TFC FOR RWY 24.) I WAS THEN APPROVED FOR R TFC TO FOLLOW A SMT ON L DOWNWIND FOR RWY 24. I DID NOT SEE THE SMT BUT ASSUMED IT WAS CLOSER TO BASE. I TURNED R BASE 1 1/2 MI E OF THE RWY THRESHOLD; ASSUMING HE HAD TURNED BASE. HE PROMPTLY NOTIFIED THE TWR THAT I JUST CUT HIM OFF ON FINAL. (MY PAX WAS SICK AGAIN). IN THE FUTURE; I WILL CARRY A SICK SACK; FLY TO THE ARPT BY NAVAIDS; NOT DEAD RECKONING; LISTEN CLOSER TO THE TWR COMS; AND TRY TO NOT LET CABIN OCCURRENCES DISTRACT ME FROM FLYING THE ACFT WITH THE UTMOST OF MY ATTN.