The dreamfeeds are tough to do. It took about a week for my LO to catch on with the dreamfeeds. I didn't breastfeed my LO, I pumped BM for all the bottlefeeds so I didn't have any latching problems. I'd used the bottle nipple to tickle his lips and cheeks to get him to open his mouth and suck. It took alot of practice and of course, every once in awhile, my DS would wake up during the dreamfeed and take forever to get back to bed. But after a lot of practice, he'd fall back asleep quite quickly. Or sometimes, DS would wake up before he dreamfeed waiting for me to give him his dreamfeed. I agree your stress level does go up but once you and your LO masters it it will get better.
I didn't do the cluster feed but I think you do the cluster feed when you LO is awake not asleep.
HTH
Mel