use something like vscode with ssh - remote to code in a real editor with proper linting, or code in a proper environment and then use a git repo to deploy to the pi, idk. If what you are doing is basically ssh-ing to the device and opening a console editor (a well set up vim does have linting, but anyway) it's no wonder it is being hard to work on it.
It's better to invest time investigating proper tools to work on than to bruteforce the work and then spend tons of time hotwiring everything. Hotwiring code is not the end of the world but if it reaches a point where the tools frustrate you, search for alternatives dammit.