Pilot reported a near midair collision event during a VFR flight under approach control routing.

Narrative:

I was on a recent flight from ZZZ1 to ism. The departure and cruise was uneventful. However; when I got closer to orlando traffic picked up a lot. I was handed over a few times and the frequency was busy with requests and instructions. Orlando approach gave me altitude changes and heading vectors. They initially gave me runway 33; but that would have given me a huge quartering/gusting tailwind; so I requested and was provided runway 6. They were routing me around and provided me with progressive heading changes. I was already in a turn; when they gave me another. Luckily I saw movement over the top of the wing and caught sight of fast moving traffic really close in. I pushed over quickly; and notified approach 'altitude deviation for traffic'. They just responded with a handover to the next frequency. I can't remember if that was the southern frequency or ism tower. I continued with the task at hand; followed instructions; and made a remarkably good landing. Once at the hotel; I checked my track and traffic online. At that point when I pushed over; there was 175 foot separation between me and the airplane that passed over the top of me. This left me a bit rattled. Yes; I was in VMC; but I was also under active routing by approach. What do I do? Report it? Chalk it up as angels of mercy flying along me? Learn to question every move that ATC gives? I did learn that I am PIC and the only entity responsible for the safety for me and my family.

Original NASA ASRS Text

Title: Pilot reported a NMAC event during a VFR flight under Approach Control routing.

Narrative: I was on a recent flight from ZZZ1 to ISM. The departure and cruise was uneventful. However; when I got closer to Orlando traffic picked up a lot. I was handed over a few times and the frequency was busy with requests and instructions. Orlando Approach gave me altitude changes and heading vectors. They initially gave me Runway 33; but that would have given me a huge quartering/gusting tailwind; so I requested and was provided Runway 6. They were routing me around and provided me with progressive heading changes. I was already in a turn; when they gave me another. Luckily I saw movement over the top of the wing and caught sight of fast moving traffic really close in. I pushed over quickly; and notified Approach 'altitude deviation for traffic'. They just responded with a handover to the next frequency. I can't remember if that was the southern frequency or ISM Tower. I continued with the task at hand; followed instructions; and made a remarkably good landing. Once at the hotel; I checked my track and traffic online. At that point when I pushed over; there was 175 foot separation between me and the airplane that passed over the top of me. This left me a bit rattled. Yes; I was in VMC; but I was also under active routing by approach. What do I do? Report it? Chalk it up as angels of mercy flying along me? Learn to question every move that ATC gives? I did learn that I am PIC and the only entity responsible for the safety for me and my family.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1738797
Time
Date	202003
Local Time Of Day	0601-1200
Place
Locale Reference	ISM.Airport
State Reference	FL
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft Low Wing 1 Eng Retractable Gear
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	Visual Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	Cruise
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Private Flight Crew Instrument
Experience	Flight Crew Last 90 Days 35 Flight Crew Total 250 Flight Crew Type 110
Events
Anomaly	ATC Issue All Types Conflict NMAC
Miss Distance	Horizontal 200 Vertical 0