Like others said, sounds like you need a vacation.
There are no perfect clients
I have had some very good clients - Some move, lose jobs so on and so forth. Yes, it is going to hurt when you lose a client or worse yet when they take the service then do not pay, case in point shopping center, good client but one of their anchor tenants went bad and by the time they collected rent the owner started missing mortgage payments...
Or, I have another client that was completely ripped off by the asset management company. The asset management company got to be slow pay then no pay then wiped out the owners bank accounts and skipped the country. I have met the once faceless owner and he swears he will get everyone paid but as far as i know all the vendors are due a couple of months.
There is safety in numbers and you have to keep the sales pipe flowing.
I have a mix of client bases.
Like I said, welcome to the world.