I have Fibro. And the bug-like sensation went from the top of my head to the bottom of my feet. SO ANNOYING! I also have IBS. What blood tests did they do? Just a CBC or did they test for things like Rheumatoid arthritis, lupus, lymes disease etc...?
Some doctors believe in Fibro some don't so I would call around to Rheumatologists and/or pain clinics and ask if they treat Fibro. I have had every test under the sun and they all come out normal. Some doctors completely disregarded a Fibro diagnosis and others didn't. But believe me it is real not just "in your head!"
I was in so much pain at one point I couldn't lift my arms to wash my hair, get dressed and even walk at some points. I could list all my symptoms but you'd be reading forever

. I am now on a medicine that has worked wonders. Try not to get too panicky because I had the same feelings about what it "could" be. Take it one day at a time and don't give up.
Catch it early because mine just kept progressing.
Bella