Should I worry about this pipe insulation? (fiberglass vs asbestos)
Quick test: go outside with a mask and safety glasses, hold at arms length, fiberglass will melt and form tiny beads in a propane torch flame (or perhaps one from a butane lighter), asbestos will glow yellow or white hot without noticeable melting.

Pull a few strands out (while wearing a particle mask) and test them. Normally, I would not advise you going into a site with possible asbestos and disturbing it, but you already have entered it, and live there.