Practice metta for the bugs, patiently endure their activity on you by observing your mind, intentions, and feeling that arises from their activity.
I refuse to use a mosquito net and the like, and I've had times where I could count a dozen mosquitos and other bugs on me while meditating outside. It's not easy but it brings benefit.
What you have is fear, and the more you do this type of activity, the more you realize the far majority of our fear is irrational, bugs and animals don't really care about you, they are not out to personally get you, they are just doing what they do, which most of the time has nothing to do with you.
I've had all kinds of creatures crawl all over me, never had any problems. I also come into close contact with bees and wasps and I often have large spiders in my room, and by close I mean within a foot, and since I'm calm and going about my business, they go about theirs.
Worse comes to worse, get one of those Sansbug mosquito tent/nets, and use that, but I suggest at least spending SOME time out in nature without trying to separate yourself and follow your aversions.