Call the COPS!! You need to get this on record. Keep all the texts!!
He is scary. You block him he finds the number. Then texts you from other numbers?? Really. There is laws against this. He can not do this and I would get some kind of restraining order against him. Once you have this on record if he does it again he can be arrested. He is seriously ill and I would not allow him to keep doing this to you.
It will Escalate!!! Please take this seriously, he is unstable and it will eventually get worse. ((((((((((hugs)))))))))