Hi, hopefully someone can help me here...

I am a fairly well travelled man having been through several Aya journeys, DMT, 5meo-dmt and changa sessions.
I first smoked Changa about 6 months ago, and have smoked probably 10 or 12 times since then, really enjoying the amazing visuals and connection to the bio-systems I feel every time.
The last 3 or 4 times I have noticed a nasty side effect that seems to be recurring, and it is not specific to a certain recipe as it happened after some from the UK and a batch from Australia.
The journeys themselves are always amazing and I have had several recurring visits from a dancing Goddess who feeds visuals directly into my third eye as soon as I manage to release the ego.
The nasty effects usually happen 3 or 4 hours after the journey has ended, sometimes up to 8 hours later.
The first sensation I get is on my skin, where it starts to get really sensitive and scratchy, kind of like when you have flu. This can also be accompanied by a headache.
After that my chest tightens, not wheezy, but just really constricted, like it is a major battle to breathe.
Usually these effects happen at night, and I try to go to sleep but end up tossing and turning and feeling really uncomfortable.
It definitely feels like something in the mix is affecting my nervous system in some way to cause this reaction in my lungs and on my skin.
Is there anoyone here who could shed some clarity of the situation, and hopefully offer advice as to how I can avoid it as I really want to continue my explorations with the spice but obviously not at risk of doing any sort of nerve damage or having to endure these effects every time..

I have generally been smoking about a 1/10th of a gram of the changa mix in a pipe or bong.

Thank you, your advice will be appreciated.

T (South Africa)