Move 7: White’s move seems like a mistake. It’s my understanding that White has two options here: D14 (the full triangle) and E15 (the ladder shape). Kata’s suggestion appears wrong to me. White’s initial mistake sets you up with a good chunk of corner territory without any significant bad aji.
Move 18: This move is OK but a bit passive. If you’d made the honte shape on Move 20 then it would transpose to an approach-and-kick result – but if White had approached low you’d have just keima’d away, not exchanged a kick and stand due to White’s top side wall. Therefore the kosumi is as though White has outwitted you a little. Instead, Q14 would be quite typical to avoid making bad exchanges.
Move 20: The strong shape here would be at Q14 or R14. In this particular position, as Black in a handicap game, I would choose R14 to minimise the aji in the corner. But Q14 gives you more strength if White tenukis from the top side and you mount an invasion there. The three space extension is not terrible but it’s sort of flimsy, there is no need to leave bad aji there.
Move 22: Not a bad move, but it’s important to see that its position constrains how you want to respond to White’s 3-3 invasion.
Move 24: The easiest and most intuitive way to play would be to block on the inside, using the D9 stone to surround territory.
Move 28: This is, imo, the worst of all the 3-3 joseki you could have played in this global position. If you play the honte third extension then you lose the corner, you lose sente, and you lose the efficiency of D9.
Move 30: It’s a nice idea to try to make D9 work for a living, but I don’t think you can play this way since White has the D5 ladder.
Move 33: White not taking D5 screws his position; this means you got away with your overplay.
Move 36: Too loose – just extend. You don’t need any fancy tesuji here: it’s perfectly desirable to allow the weak group to run out and to harass it responsibly with thick shapes. You’ll notice that Kata only cares about this cutting point for a long time, because it’s a major defect in your shape.
Move 49: This is quite risky by White. The honte thing for him to do would be to hane over the connection and then perhaps connect into a full triangle, making miai of extension on the side or a jump into the centre. Normally Black would now hane over the attached stone, but in practice you still have that F6 cutting point that makes a lot of the bottom side stuff irrelevant.
Move 64: You can now play E12: you have captured the White group, you win the game (if you can manage to kill it.) As we can see, P14 doesn’t even secure your territory that well.
Move 70: P13 seems like the move here. Just connecting against the peep is quite passive in this position
Move 76: I can’t really see the purpose of this move.
Move 84: Even if this cut worked, there’s no need to be this reckless. If White just connects at F3 then he lost sente for quite little.
All in all, you got an early attack through a gift from your opponent, but when the critical time came you didn’t follow through. It’s odd to me because when you played G12, it looked very much like you knew what you were threatening.