Jeans can get away with going two maybe three wears without washing if I was just sitting at work all day, but everything else gets washed after one use. Simple green can do wonders for clothing that has been saturated with oils and dead skin, I use it on my more rugged cloths that I've been doing car/yard work in; and it's stupid cheap for a large jug, less than $3.
I have two towels that I'll switch between half way through the week, and always let them hang open over something to completely air dry after use.
Sheets get washed/changed every two weeks, three at the longest (or after "activities").
I use unscented everything when showering (shower EVERYDAY, no exceptions), mixing smells is not a good idea. Also, some scents just don't work with your body chemistry; I've tried on cologne that smelled great on the paper strip, but turned bitter once it met my skin (shame to... It smelled incredible). With all that being done, if you only have one scent on it's easy to figure out quick if it's not a match and making you smell "weird".
I know people with the same issues as you, they just don't really find this stuff important for some reason. They're good people, just need to spend a little more time taking care of themselves.