I personally don't believe that there's much gold to be found in dream-reading, but I learned a bit about dream interpenetration in a Literature class of mine, and I think it's a fun little pastime.
The whole section about the procedure makes me think that you have a big goal up ahead. Something that you're willing to risk things for, and something you desire incredibly. You may even put yourself at risk to attain this desire. Even though in this dream you were undergoing a (seemingly) medical procedure, that doesn't necessarily make your goal medical at all. You could be perusing a relationship, either romantic or platonic. You could want to join a certain group or such. However, whatever this goal may be, there's some sort of backfire that you think you can overcome.
In the dream, you go along with the procedure, but later doubt your decision because it is too much. You realize the danger and feel you need to draw back, but something is keeping you. It could either be a change that you absolutely cannot alter (a bad example, but it will serve the purpose: you decide to get a tattoo, but it gets very painful half-way through, but now that you have half of it you can't get it removed), or a change that you technically can alter, but don't have the willpower to.
When you say "bugs", it's hard to tell what kind of bugs. All sorts of bugs have all sorts of meanings, but I'll try to just generalize the term "bug". A bug ids something that bugs you (pun intended). It can be anxiety or worry. Stress, even. The bugs burrowing into you seems to indicate that something is worrying you, on one level or another, to your very core. You've been stressed about this upcoming goal of yours, even though it's something you want very badly. But you fear that if you follow the desire, you'll want to back out later.
This dream is about a trial, for sure. Whatever your trial is (if you have one), I wish you luck! Before springing into it, make sure that you have a fair understanding about whatever it is you're pursuing, and make sure that, in your heart of hearts, it's what you want the most.
