This is a tough one. I can't offer much advice on how to solve it, but if I were you, I would shoot a throwaway roll or two and cut it up in 2 or 3 pieces to develop one at a time. Trying to solve the problem by working on photos you want to keep only adds to the frustration and anxiety. Leave your keepers undeveloped until you solve this.

Oddly enough, my nemesis is digital. I have been trying to scan colour negs and print them for several years now, with only marginal success. I can hear your frustration.