I went the same path of writing a text editor from scratch. There are a lot of moving parts, so I tried to outsource as much features as possible - LSP for intellisense, tree-sitter for highlighting and syntax-aware features, fzf for search and file handling, etc. I also tried to design it so that it can be tweaked to one's needs with simple code changes, suckless-style.
It was indeed a pain using it for the first few weeks, where every 5 minutes I found some bug and had to go back and fix it, instead of steadily working on some other project. Good news is more bugs you fix, less bugs is left.