So now I'm left with small stumps and Im keeping my fingers crossed that they will live cause some of them have roots already... I'm more worried about the ones that haven't rooted yet... :-(

I'm really sorry that happened :( I hope your remaining parts make it.

Something that may help in the future is planting the plant higher in the pot, thus giving you more growing room at the bottom, as well as reducing the amount of empty space at the top of the pot. That space can really heat up and reflect onto the stem like an oven.

Also, you can cover the stems with aluminum foil to keep the sun off.

Good luck and again, sorry for your setback. Please don't give up, it's a learning process and we have all felt your pain being in similar situations.