"When smoked, DMT effects are shortlived and intense and the smoke is harsh and plastic tasting. Because of the quick onset, it's important to try to breathe the smoke in deeply. If you wait too long for a second hit, the effects may have already begun...and once they have, it's unlikely you'll have the opportunity to take another hit.
Many people find the most effective method for smoking DMT is to use a glass pipe and inhale deeply. Often, the DMT melts and some of it remains behind in the pipe. This can be a problem if you load a full dose at a later date and unknowingly have an additional 20 mg left in the pipe. One person has recommended prewarming the pipe. In theory, this will prevent the vaporized DMT from depositing on the cold glass of the pipe. Another recommendation is to put a second screen on top of the DMT so the flame doesn't burn the DMT (resulting in loss of material)."
From Erowid. Half of .2 grams is 100 mg. An extremely large amount of material. I'd imagine that your method is either inefficient or the material has some impurities. Or a lot of impurities.
EDIT: I see now that you used that 100mg over two trials. Nevermind this statement.
My method is as follows. I use a standard glass bubble pipe, pre-warmed. I load 20-60 mg of DMT(sixty is quite a bit, I've just got a pretty serious tryptamine tolerance). I slowly heat the pipe and allow the material to be completely vaporized. In one to three inhales I consume the smoke quickly. Holding in the vapor for maximum effect. Be sure you're in a safe place, preferably sitting down on a bed or something you can lay back for.
I would try it again, maybe 20-40 mg, and try to stick to my method. If you don't have one, by a real pib. It's much better than a light bulb.
A key is to not consume any tryptamines in the few days before using DMT. One to two weeks is a safe bet to wait since your last try. DMT tolerance builds extremely quick but fades fast.
Try reading some of the experience reports. Every method works differently for everyone.
Your dmt should look something like this.
