This looks like a good game to learn from. Go is fundamentally about territory, and at some point you have to try to make some of it. Maybe it will fall into your lap through a brilliant attack which actually kills a big group, but more often you have to think about where you can make territory and then try hard to get it.
Lets looks at the sequence in the upper right after

. How would you describe the starting position? Here is what I see: 1) W has an extremely strong group radiating power to the center and the upper right; 2) W has a corner shimari facing the upper right; 3) B has three very weak stones in this area. Clearly W has an overwhelming local advantage, which should somehow be turned into territory.
Now jump ahead to the result after

. How would you evaluate this position, compared to the start? B has succeeded in making a very safe almost certainly alive group. What did W get in return? The very strong W group has become a little bit stronger, but that is all. W did not enclose the weak B group (which would make center strength) and W did not make any corner territory. Clearly something went wrong.
The basic problem is that you attacked the weak B stones by pushing from your strong group, which is the wrong direction. The right strategy is to push from the weaker side, forcing your opponent in the direction of your strong group. Also, the top is where there is territory to be made, and now is a perfect time to take some profit while attacking. There are lots of possible moves, but how about something simple like R14? If the sequence unfolds R14, R13, R15, Q12, then B has nice shape (although you can mess that up with a peep at P13) and will probably live, just like in the game sequence, but this time you have a secure profit of 20 points in the corner.
Something similar happened later in the upper left corner, where you started out with a good position but did not find a way to make territory. You cut B with moves

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, initating a strong attack, which should have been profitable. Clearly after the cut, the W groups on either side are much stronger than the floating B stones. But jump ahead to

and B not only lived, but ended up with more territory than W along the top.
I think the problem was again direction of play.

was great shape, but very slow, letting B off the hook. How much harm can B do by running with this stone? Certainly no harm to the right, where the huge W wall is waiting. On the left side, you might worry a little, but you still have plenty of room, and in fact you would not mind running toward the bottom side, since that would destroy the potential B territory there.
In the other direction, along the top side, there is a lot of territory waiting to be made, and now would be a perfect time to beat your opponent to it. You should be able to make territory there naturally, while also loosely attacking the big floating B group which your cut has created. How about playing somewhere around H15? There is a very good chance you can make a big territory here, as it is unlikely B will be able to invade while he is busy settling his weak group. It was a real shame to let B destroy all this prospective territory while settling his group nicely with

. (Even after that, I would respond at H17, to try to dispute the territory around here. If that failed and my group died, I would resign.

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are too submissive and painful to even consider.)