Seat 2: beabea11 (6,100)
Seat 3: Kvald777 (8,380)
Seat 4: acampagnone (3,265)
Seat 5: rainmanrcp (2,140)
Seat 6: jonny4107 (3,113)
Seat 8: bigftbl88 (1,795)
Seat 9: thr2301 (9,680)
Kvald777 posts the small blind of 50
acampagnone posts the big blind of 100
The button is in seat #2
*** HOLE CARDS ***
Dealt to rainmanrcp [5h 6h]
Daniil 33 sits down
Daniil 33 adds 2,755
rainmanrcp calls 100
jonny4107 folds
OxyOldeboy sits down
OxyOldeboy adds 2,145
bigftbl88 folds
thr2301 calls 100
beabea11 raises to 200
Kvald777 calls 150
acampagnone calls 100
rainmanrcp calls 100
thr2301 calls 100
*** FLOP *** [7d 4s 3s]
Kvald777 checks
acampagnone checks
rainmanrcp bets 350
thr2301 calls 350
beabea11 folds
Kvald777 folds
acampagnone calls 350
*** TURN *** [7d 4s 3s] [As]
acampagnone checks
rainmanrcp checks
thr2301 bets 100
acampagnone calls 100
rainmanrcp folds
*** RIVER *** [7d 4s 3s As] [6d]
acampagnone bets 100
thr2301 raises to 5,300
acampagnone folds
Uncalled bet of 5,200 returned to thr2301
thr2301 mucks
thr2301 wins the pot (2,450)

Should have I protected my hand and overbet the flop? My fold on the turn is foolish as far as pot odds go, but that bet says to me that he definitely just made a flush underbetting so much which is also supported by the mega reraise on the river. Is it looking like this fold was a reasonable play or should have I stuck around and try to showdown without getting it in?