Woah, lots of replies. Ok.
Could be a diet thing man, do you eat well?
I eat very well. I could eat more veges, but other than that I eat really fucking well. I have a fair amount of fruit, everything is brown/wholegrain, everything is real food that's cooked, nothing processed.
If you can deal with it, shaving your armpits can help with both perspiration and smell, as it lets the deodorant make direct contact with your skin rather than getting all caught up in the hair.
I'll try this. I 'trimmed' them (shaver set to like 3mm or something) and that didn't do anything, though.
One other thing - I almost never stink when I sweat, and I'm pretty sure it's because I drink a truly absurd amount of water daily
I usually drink about 2L daily, more if I go to the gym. I'll try drinking more though.
For excessive sweaters, sometimes a buildup of old sweat/odor can occur in the under arm material of your shirts that normal detergents can't remove. Once you put on a 'clean' shirt and start sweating your shirt will absorb the new sweat pushing out the old aged sweat. This creates a strong odor very quickly.
No amount of deodorant will stop you from smelling if this is the case.
Try washing all of you shirts in hot water and add a cup of white vinegar.
Then put through a normal wash with detergent.
This will get your shirts super clean and smelling fresh.
change the type of 'shower in a can' you use every now and again too.
My 2 cents.
Honestly this sounds like it's probably a major factor. Even a tiny amount of sweat produces a huge amount of smell, especially in a few of my tshirts.
What's 'shower in a can'?
Also try to not use t-shirts that are too tight in the pits, as it will keep them too closed and will smell like a motherfucker.
This is a bit of an issue too. I've gained a bit over 10kg this year and I'm still wearing the same shirts. But I like them!
Also, I should probably start showering in the morning. With temperatures rising I'm sweating at night, then waking up expecting to be perfectly clean. It's just weird that this is a new thing, I can't think of anything that's significantly changed in the last 3-4 months that could have caused it.