Preflop: I probably just dump this preflop. If you really insist on playing it, probably at the least raise it pf, but i would just dump it.
Flop: Looks fine, although you can see the problem with playing a5... you only have a 5 kicker.
Turn: Lucky you. Looks fine, i might actually bet a little less like 3.50, but it looks fine.
River: Don't check! If he has Ax (pretty good chance he either has this or the busted flush draw), and most good players don't bluff their busted flush draw here, so most good players are checking behind here and you are losing lots of value. Vbet the river for like 9. As played, i probably raise his river bet to like 22 or something small in hopes of a call. I don't think a call is too terrible though... although your probably losing value.