What you describe sounds to me like
withdrawal symptoms initially (the brain zaps, etc), but the later
symptoms (chest pain, etc) sound like classic rebound anxiety, which is very common after d/c-ing these meds.
I understand that you're in a rough spot b/c of the inability to afford the care and meds you may need, but I would strongly recommend looking into what options may be out there for you...financial assistance, etc.