I am a big believer in following your gut and your heart and paying attention to dreams and signs. In fact, my intuition is the tool I am relying on the most these days. So if your soul says fast, I say fast!
I lost a lot of weight doing the MC also. Unfortunately it did not save me from gaining as I mentioned the 60 pounds in 4 months. And you're right, that type of weight gain is totally Lyme.
Also, I am one who has battled insane food cravings. All the bad stuff you mention. I was addicted. There was an incident involving about 40,000 Kit-Kats that I shall never speak of. LOL
I never believed how much the cravings were Lyme until I started getting better and dealing with the systemic candida in a successful way. I had tried the raw diet and fasting, but these were only temporary fixes and ended up backfiring. What's worked for me has been slow, steady progress in the cravings department and what do you know - now that things are working, I am losing my cravings naturally and the weight is falling off, despite no change in my eating habits. Oh please, let it continue!
I will tell you that my diet right now is not great, but it's not terrible. I decided after much agony to let the diet recorrect itself naturally. Takes longer, but for me it's ultimately more sustainable.
Best of luck to you on the MC - doing the MC is definitely something to be proud of because it's not easy and also that's great that you are getting the benefits and the body gets a break from the food allergies. It's also nice because thinking can be clearer on the MC, which is a huge benefit with Lyme.