How sufficient are these steps to prevent deleted SSD files from being recovered?

I’m selling a 4-year-old Dell PC with Windows 10 and two SSDs and I want to be sure that nobody can recover anything from my personal deleted files. So far I’ve done the following.

  1. Completely Bitlocker encrypt both disks, including unused space. (Note the machine did not have TPM so I had to use a password)
  2. Uninstalled software and deleted all personal files. (For sake of discussion, let’s assume I didn’t miss any personal files.)
  3. Created a new, Administrator-level account
  4. Logged on to the new account.
  5. Completely deleted my previous user account.
  6. Completely Bitlocker DE-crypted both disks again
  7. Completely bitlocker encrypted and then decrypted both disks, yet again.

My idea was that if Bitlocker full-disk encryption/decryption really touches the whole disk, then two rounds of encrypt/decrypt out to overwrite everything. But I don’t know if I understandit correctly or even if SSDs truly work like HDDs in that regard

Is this good enough? Is there some other step I can take that doesn’t involve buying some expensive tool?

I can’t sell this encrypted and I want to leave Windows 10 on there so I didn’t want to completely reformat the system drive.