For those that are unable to pay for services, call your local Health Department - they are there to help, this is what they do. If elderly, the Department of Aging will help you out too. There is help out there, sometimes all you need to do is ask and make a few phone calls. Common sense and a good Google search doesn't hurt either.
My girlfriend lost all her upholstered furniture, had to rip out the carpet and had to dispose of all her beds. Cats had to go to the vet then I took them till the process was completed. All her clothes had to be quarantined and laundered. This is a professional woman that picked them up in a high end hotel on a business trip. Even though she could afford the service, there she was in a ripped up bare house. Took her 5 years to replace everything.
https://www.webmd.com/skin-problems-and-treatments/guide/bedbugs-infestation#1
Call in the pros . . . You will never be truly rid of them otherwise.