Since visiting a therapist seems not plausible, it’s very important, along with blocking his number phone (you don’t really need of that $hit more), looking for support on friends and other loved people is very helpful. Very important that you can talk to a person you trust and telling her/him what you are trying to do, that is, zero contact. They can help you to stay strong because I guess it’s not easy what you are going through. Trying to meet other people to hang in with is also a good idea so you will see there are people who you can have healthy relations with.
Coming here to say how you are feeling or writing down on a journal each time you think of him and want to contact him or that he contacts you.