Frogman, without knowing the whole story, I have to say this: If you are running 100+ domains with databases, cron jobs, and other stuff, you really need to get your ass off of shared hosting and onto your own box, where you would be basically master of your own world, and whatever issues exist would be from your own stuff only.
Very likely your original host assigned a very small amount of resources on a shared server to you, and you far exceeded what they expected.
But continue.
Drama Llama is amused.