Well you should stop sleeping, because you body uses it every night. So please stop before you make a utter fool of yourself
OT:
Dude the first time I actually broke through it took almost 150mg using the "Machine"(Google it). I tried 3 times before starting at 25mg, but I could never get all the way through. But honestly when I did, I never felt the way I did, and to this day I'm a completely different person because of it.
The best way to take it personally is:
With a very close friend. Just one!
Very quite relaxing room. No music, distractions, or loud noises!
Binaural beats, to fade away some background noise.
Smoke your dosage as fast as possible; I usually take 25mg doses, and have my friend get each dose ready as I taking one.
After smoking, relax completely, lay back, and close your eyes.
If your able to break through, write down what you saw/experienced, so the memory stays with you!
DMT is a very special molecule, and if used correct can teach you a lot. I've had almost 250mg for the past year I have no desire to use, my last break through opened my minds to things I couldn't believe, and learned all I can from it at my current moment in life.
Good luck!
Also about cross-tolerance, I may have some effect due to it structure. I know from experience it can dull mushrooms while being on them, though I never noticed anything afterwards, especially not LSD. Though not much dulls LSD for me, so it's just speculation.