It looks a lot to me like the story of the first game is the story of your opponent getting luckier with his Potion and his Familiars than you were. He played 2 Familiars on turn 7. You played one on turn 9, and he promptly played one back at you on turn 9, and then again on turn 10. So at that point you've sucked down 4 curses, him just 1. That's a nasty deficit, and while you eventually closed the gap a little, it was too little, too late. I don't think there's too much you could've done. Your Potion missed the turn 5 reshuffle.
The second game looks a little less well-played to me. Your turn 8 gives you $8 and you already have a Gold in your deck, and you go for Gold. Turn 11, you turn $9 into a Platinum. You could've had a 3 Province lead at that point!
He gets a little lucky, capitalizing his first Province, turn 11, into a Trusty Steed turn 13, but in all fairness he is using Havens to finesse the Tournament race. And then he gets QUITE lucky and re-capitalizes the same Province on turn 14, still with just one Province in his deck, into a Followers.
But you weren't playing coherently. You either needed to commit to Provinces, in which case you should've had 3 Provinces at that point instead of 1, or commit to Colonies, in which case you should have had 0 Provinces instead of 1, and also you shouldn't have had Tournaments, which are too-low-buying-power to hit $11 in a reasonable time.