I find this castle very good looking.
I had this idea first too and build a big keep from my own old classic castle sets from the 80ies. Unfortunally, I had the same problem as you. So I improvised and improvised untill it was quite good. I liked it, but I wanted to build a greater castle. So I collect set after set over the years to have enough pieces to build a great castle (like castles from DNL and Teddy), but now I have not many space to build a castle and to place it on somewhere.
I'm even moccing a town house since januari, but I'm busy with other things that come trough, so it's still not ready.
So, I can feel for your Doomfeelings, but maybe you can make a better castle in the future, when you have more grey. You made great mocs since you came here so keep up the good work.