another vote for mites here...looked just like my problem I had a few months back.
SNS209 works ok for preventing them, but at this stage you will probably need stronger measures
Azamax works great, as a safer alternative to the many many chemical solutions out there. I found azamax to be expensive, but you do not need a lot, and usually just 2 applications is all you need to eradicate the infestation.
Keep in mind they will be back if you bring them back (ie from outside on your clothing.)
Change your clothes and brush your hair a little before you enter your garden, and keep others out as well.