Before formatting your SSD, you must be ready to boot on a flash drive for the next installation. With a bootable installation USB drive you can format the SSD just before the installation.
If I understand you correct, your Microsoft Account is blocked and unrecoverable?
Don't you have a phone number or another email address to recover that account? If so...
1. Create another Microsoft account and make sure to add a phone number & an alternative email for recovery purpose.
2. If you have a licenced Windows 10 Pro DVD, create a bootable USB flash drive with it. You can skip this if you can borrow an external DVD drive.
3. Proceed with the installation.