Playing a big stack..help needed!

[KKsuited]

Well I posted a few days ago about my catastrofic meltdown. Long story short, 90k with 5 people left, second at 39k. I finshed 5th.

The good news is, I getting my hands on a big stack. The adjustments I've made (not slowplaying, not check-raising, raising a lot of pots) has helped me a ton. The last 2 tounries I've played I dominated the first 3/4 of the tournament.

Again tonight, I moved my stack from 10k to about 65k pretty early in the tournament. It was a sat. that paid the top 4. I did finish in the top 4, which is good.

My question is how do you guys play with a big stack? I was the cheapleader for most of the tournament. Most of the time I maintained a 20k lead. But then I ran into a set, AA, etc. Long story short, I crawled into the top 4.

I dominated 90% of the event, but barely made it.

I play pretty aggressive, making it expensive for small stacks to see the flop. The problem I have is I run into to many situations where I raise 4k, then have to call 3k more when someone goes in on me. I usually have the worst of it.

What is to aggressive with a big stack? At some point, I guess players lose their fear of me a really start to play back. Should I be playing tighter with a big stack?

I never had this problem before. In the past I've been able to close strong. Now I come into the final table strong, but can't hold on.

Any thoughts?