Heads up 3 consecutive plays - 3 losses - did I do a mistake

I posted this in the NL Hold'em forum but I think this is a better suit since it was a short handed game to begin with (4 players). It's a bit long but bare with me and tell me where I ****** up.

First let me say that I'm fairly new to actually playing poker for real money and you just can't compare playing for play money or for cash.

So this was actually my 2nd game of poker. We were playing live (I don't play on line cause I know it would suck me it completely ) and we started with 4 players.

It's not high stack it's buy-in 10 euro (around 14$) with the chance of rebuy within the first hour for another 10 euro (if you go broke) and after the first hour passes everyone can buy for another 10 euro (so 42 ish $ total).

Blinds are 0.10 euro (0.14 usd)/0.20 euro (0.28 usd). So I went into the heads up with 80% of the chips (total of 80 euro on board) Blinds rose to 0.50 (0.70)/1.00(1.40).

First game was me AKs in the SB, betting 10 euro and he calls. Flop comes AQQ and he goes all-in. I counted my outs at the 2 aces remaining in the deck and the close to zero posibility of KK on turn and river as I put him to a QT or Q9 I folded. He showed me K9s. So now we were at around 70/30 in chips.

Then he went all in with me having K6o and I folded.

Next was me having pocket 99 and I went all-in, he called with AQ and nothing came up except a Q so he got 70/30 in his favor now.

Next hand I get a AJs and go all-in. He calls with.... KK and I loose.

It's not actually about the money cause I lost like 28$ but I wanna know if I made a mistake. Here's my reasoning behind my choices.

I was playing tight aggresive for almost 2 hours when I turned in a massive chip leader when a face to face (cheap 2 euro raise) came AQT with my KJs - if the queen were of spades I'd have a royal . So I raised another 2 euro and he calls, turn comes K. I raise another 2 euro he goes all in and I call. He had AQ 2 pairs I had a straight. And then I started playing a bit more loose but still very aggresive and I kicked the 3rd out.

The guy that was playing me in the heads up was playing (I played vs him before and watched him play once) loose and switching from aggresive to defensive all 3 nights.

So that's why I raised 10 euro (around 1/2 of his chips) on AK and lost to a bluff.

Then I went allin with pocket 9's and lost vs 2 over cards but I still think it was a good decision since pocket 9's are a very good heads up hand.

And then I went all in again with AJs which I still think is a good hand for heads up and lost again.

Did I make a mistake anywhere I hope I gave enough info on the players.