I pop an Ativan to take the edge off the clanging and banging noises and I find that if I never open my eyes while I am inside the tube I am completely fine.

Try taking some deep belly breaths while inside-- concentrate on slowing your breathing down as much as you can. As you breathe in say to yourself "in goes the positive" and as you breathe out say to yourself "out goes the negative." If your thoughts drift while you do this, don't beat yourself up...just go back to the mantra and focusing on your breath.

Good luck Dejibo!