I think you are right – you will regret the wasted time more than you will regret not having finished, I believe.
I don’t think that degree will help you with anything if you don’t want to ever work in Architecture anyway. I think your fears are only the echo of your father’s voice telling you what to do, you are scared of disappointing him and of the outcome of not doing what he says.

Personally I regret the time I have spent studying Architecture and wish I have changed direction sooner, although as I said it wasn’t the end of the world either that it didn’t happen sooner. I finished my first degree but didn’t go all the way and never worked in Architecture, it just wasn’t for me. The difference is I didn’t know what I wanted to do instead and it took me a while to find out, so while I was still searching for what I wanted to do I kept with it. But you already know, so if the only thing stopping you is that fear of not finishing it, I would say go for it, life’s too short to stick with something you hate.