Yeah, I was in the same boat as you. My dad, friends, etc had told me that they all like the Demon, but its definitely something you should only do every now and then. I was stupid, and a friend of mine started cooking, and I basically turned my lungs to plastic over the next few weeks. This, combined with other psychedelics, mainly LSD once or twice a week and 2C-P every couple of days (there is no tolerance built to 2C-P), put me in a REALLY bad head space. DMT has made me see some amazing things, and I would personally love to try ayahuasca. However, I would personally turn down a bowl of DMT if offered right now. Hell, I can go get some resin out of my old DMT bowl and smoke some right now. It just put me in too bad of a space. I thought people were stealing from me, among other things that all turned out to be unfounded. It is because of this recklessness earlier in my life that has made my current psychedelic use very touch and go, although I have been going pretty hard lately.
In terms of DMT tolerance, I personally felt like my friend and I gained a tolerance very fast, but then again, he was cooking it and we had a lot of time to waste, and I'm sure we smoked more than the average Jose.