Hello and welcome!
50mg can be a
very strong dose sometimes. Start lower. 30mg or less should get you there once you get the hang of it. It's very much dependent on vaporisation technique.
Hold the vapour in for as long as you can - there should not be any visible vapour when you exhale. If you've inhaled correctly that should be a moot point anyhow.
You wouldn't be able to reload another 50mg hit if you'd administered the first one correctly. 3x50mg hits would be way too much as would just the two - assuming it's consistently possible to vapourise the whole dose in one hit with your device.
The exception is in the case of some rare people who are highly resistant to the effects of DMT owing to their personal biochemistry.
What effects have you obtained so far?
What other psychedelics have you tried?
How did you find out about DMT?
“There is a way of manipulating matter and energy so as to produce what modern scientists call 'a field of force'. The field acts on the observer and puts him in a privileged position vis-à-vis the universe. From this position he has access to the realities which are ordinarily hidden from us by time and space, matter and energy. This is what we call the Great Work."
― Jacques Bergier, quoting Fulcanelli