A couple things come to mind.
Because you pack a lot your well downstairs might not be breathing well. Look up vaginal yeast infection. If you have symptoms you can try treating this for a week. Smell is a symptom. The meds are over the counter.If you dont' respond pretty much right away (36 hours) you need to go to a doctor. I don't like to talk here about such things but you might really need this.
Second is that polymers used in cheapo packers (Mr Limpy, Sailor, etc.) are very hard on your skin and can be breaking it down. I can't use any of these. You can look for a 100% silicon packer. A few you might look into are: Mr. Right (huge but it is silicon), Pack-man (Canadian) is a lot smaller; there is something like the Perfect Packer but I can't find it; and the Basic Packer from Reel Magik. You are going to pay more than the Mr. Limpy but they are nice in that you don't have to use corn starch. I have not broken out since using the Reel Magik. (THis is not the medical prosthetics btw.) They cost more but last longer.
--Jay J
