I don't know what to do if you create an environment that crashes once, but it seems possible to start anew.
It is not possible to delete your FB account, this is only a solution for those who are stuck with a guest account.
I've only done it once, so I'm not sure if it's correct.
I was able to change the certificate using esign and ksign, which can issue free certificates.
Does your account information depend on the certificate?
You may be able to start in a fresh environment by changing the account you use for sideloading.
How do I purchase items for real money?