CLOSE PROX GA-SMA COMMUTER-LTT IN ISP ATA.

Narrative

VFR TRAINING FLT; TOUCH AND GOES WERE APPROVED BY LONG ISLAND TWR ON 33R; R HAND TFC. WHILE FLYING THE PATTERN; ATC HAD A REQUEST FROM AN LTT X FOR ONCE AROUND THE PATTERN WITH A FULL STOP. ATC APPROVED L HAND TFC FOR 33L. AS THE LTT X ENTERED BASE FOR 33L; ATC CLRED THE LTT X TO LAND. BEHIND THE LTT X WAS COMMUTER MLG WHO WAS CLRED TO LAND #2 BEHIND THE LTT X. THE MLG WAS UNABLE TO SLOW UP ENOUGH SO THEY REQUESTED A GAR WITH L TFC 33L. THE MLG WENT AROUND FOR L TFC AND BEHIND THE MLG WAS AN LTT Y ON FINAL FOR 33L. WHILE ALL OF THIS WAS HAPPENING; WE RAPIDLY TRIED TO CONTACT TWR FOR APPROVAL FOR TOUCH AND GO 33R. THE COMS WERE SATURATED BTWN LONG ISLAND TWR AND LTT X; MLG AND THE LTT Y SO AT THIS TIME I MADE THE DECISION TO FLY A NORMAL TFC PATTERN AT ISP AND NOT GAR. WHEN I ENTERED MY FINAL LEG OF THE TFC PATTERN; ATC ADVISED ME TO IMMEDIATELY MAKE A L 360 DEG TURN. FEELING THAT THIS WAS NOT A PROPER REQUEST I CHALLENGED ATC. HE CAME BACK AGGRESSIVELY; TOLD ME TO IMMEDIATELY MAKE A L 360 DEG TURN. AS I MADE THE L TURN I NOTICED THE LTT Y TFC ON FINAL TO 33L OF WHICH I HAD JUST TURNED INTO. AT THAT TIME I DISCONTINUED THE TURN AT THE 90 DEG POINT TO AVOID A MIDAIR COLLISION. I FELT THAT THE CONTRIBUTING FACTOR WAS ATC WORKLOAD. HE ALSO HAD NO IDEA WHERE I WAS ON THE TFC PATTERN AND GAVE ME DIRECTIONS THAT WOULD HAVE BECOME A MIDAIR COLLISION. ALSO; ATC THOUGHT THAT I LEGALLY COULDN'T ENTER MY BASE WITHOUT CLRNC TO LAND AND MY UNDERSTANDING WAS I COULD LAND WITHOUT CLRNC TO LAND.