Hi and welcome!
Wow, you have been through a lot! I can see you're at the end of your rope and I don't blame you. Living with an active alcoholic and substance abuser is such a draining and stressful way to live.
Well let's see. A.) He won't stop lying until he's ready to stop abusing pills. Active users are incapable of telling the truth, since they will do and say anything to get money or whatever for their next fix. B.) He's using to avoid facing any kind of reality, so him developing the confidence to live on his own isn't likely to happen anytime soon. C.) You might want to call his doctor and tell him about your dad's addiction. I can't believe he keeps handing out those pills!!! I would think he could be charged for doing that, but I'm not familiar enough with the law to know.
I know you say throwing him out isn't an option, but, why not? Why can't he live on the streets? I don't mean to be heartless or cruel. But as long as someone keeps giving him a roof over his head, he has access to money and items to pawn. If he's on the street, it might help him hit his bottom and seek help on his own. There are a lot of people here that have kicked out their A's, and many of them decided to seek help to avoid living on the street.
I know this isn't what you wanted to hear, but your dad won't stop using until he's ready, and the easier it is for him to continue using, the longer he's going to do it. Right now, between the doctor and family members willing to help him out, he's got it made.
I know I'm being harsh, but your dad is in bad shape, and the only way to help him may be to let him go and let him fend for himself.
Please visit the al-anon and nar-anon forums while you're here. A lot of us have been where you are.
Take care and keep coming back,
JG