I have no understanding of the Scotch, and I usually end up with a very awkward position in it as black. Here's one game, blitz, which I actually won, but I was the losing side after the opening.

So that's the game. Could you please give me advice on how to play this opening right? I'm completely clueless when I see it on the board.

edit: I don't know what's wrong with the pgn. :/ I remember reading there was something about how the site's pgn viewer handles comments, but I can't remember what.

It works without the comments.

And with the comments as text:

1.e4 e5
2.Nf3 Nc6
3.d4 exd4
4.Nxd4 Nxd4 {Apparently this is not the right move, but I always play it because I have no clue what to do.}
5.Qxd4 d6
6.Bc4 Be6 {I already see I'm not OK. How do I develop, where do I castle? The black-square bishop is stuck, and I'll have trouble castling long because of the queen threatening a7. And there's this e5 pawn push that just scares me to death because of all the games I've lost to it.}
7.Nc3 Qd7
8.O-O c5 {This is just awful, but I've got to castle or I'm going to be destroyed in the opening.}
9.Qd3 O-O-O
10.Bf4 Nf6
11.Bxe6 fxe6
12.Rad1 Be7 {This bishop is going to be a bad one for a long time.}
13.Qc4 Kb8 {To get the king to a8 where it'll be out of trouble. It's probably too slow...}
14.e5 d5
15.exf6+ {...Oh, yes, it was.} Ka8
16.Qe2 gxf6 {OK, so he got a knight out of all that mess, but now my position doesn't look so bad so I'm not resigning.}
17.Nb5 e5
18.Bg3 h5
19.c4 {To take the defensive duties off the queen I think.} d4
20.Qd3 a6 {I don't think this is a concession. White won't be using the hole on b6 any time soon.}
21.Na3 h4
22.Bxe5 {This has to be wrong...} fxe5
23.h3 Bd6 {With the hope of playing e4 at some point to finally activate the bishop.}
24.Qe4 {OK, for now the bishop will keep defending stuff, which is still better than doing nothing. That white queen is well placed now.}
25.Rd3 Qg7
26.g3 Rh6
27.Kh2 Qh8
28.Rg1 Rf8
29.Rf3 Rxf3
30.Qxf3 e4
31.Qg4 hxg3+
32.fxg3 e3
33.h4 Qe5 {I was in severe time trouble here. If my opponent had just played any OK defensive moves, I'd have lost on time. I've noticed that some players start to play nervously when the opponent is running out of time.}
34.Kh3 e2
35.Nc2 d3
36.Ne1 d2
37.Nf3 Qxb2
38.Qc8+ Ka7
39.Qg4 d1=Q
40.Rxd1 exd1=Q
41.Qg5 Qh1+
42.Nh2 Qbxh2+
43.Kg4 Qh3# {With 6 seconds on my clock.}