im sorry so many things have failed since your tens unit is effective you may want to look into a trial stimulator. i have 2 so if you have some quwstions feel free to fire away. one suggestion though if you do decide to have one avoid the ketamine pain pump it didnt work at all for me and with a previous history i wouldnt rely on it.
just a thought the other messages regarding the medication is probably the smarter route and i hope those work but if they dont the stim might help