Quit Finasteride after 13 yrs. BIG MISTAKE

[Localguy]

I'm 58yrs old. I was on fins for 13 yrs. and had great results keeping my hair. It was thick, fast growing and I had no hair loss all these years. It was so easy to take that little crumb every morning and I never even thought about going bald. I started it back then because of a small bald spot on my crown. My Dr. said try this pill it might regrow that spot, and it did within a few months, so I kept taking it.

Now 13 years later my new doctor asked my why I was taking that crap and that it will prevent me from ever getting an erection again. So I panicked and thought about the sides I did have and thought I better quit taking it. I used to think the ED I had was more from high blood pressure, cholesterol and being over weight and getting older.
So like a fool I just stopped it cold turkey with out doing any research and within 2 weeks I started to find hairs everywhere. Within 4 weeks I was scooping palm fulls of hair out of the drain and seeing my scalp and massive hair loss.

So not knowing what to do I started taking it again. Now 8 weeks after I quit I am still loosing hairs and I am almost completely bald on top. My sides and back have thinned out a lot also and it seems like my hair stopped growing altogether. Even my beard seems to have slowed down, I used to need to shave every morning and now its every 3 days or so. I never would have thought I would lose so much hair so fast.
I did go see my dermatologist who is a hair transplant guy, and he just said to stay on the fins. He tried to say it will grow back but wasn't very convincing.
Does anyone have any experience with regrowing hair after loosing so much this way? Is it even possible?

It seems like it fell out way too fast, could it be something else?
I have a Dr. appointment next week to have some blood work done.
This is horrible, to go from having a full head of hair 2 months ago to this and its not stopping. I can't face anybody, I know I'm older than most of you guys and shouldn't care that much, but I do. I can't believe I just stopped it without realizing this could happen, and so fast.
So being on Fins again, is there any hope?