Sounds like you, like a lot of others, have come to docker from the perspective of “it’s like a mini virtual machine”. Maybe you’ve used VMs before, like virtualbox or VMware or EC2. Maybe you have experience with setting up a cluster of VMs, each with their own OS, own SSH client, own suite of applications, and an overlay network between them all. Maybe someone told you “you should use docker instead, it’s like mini lightweight VMs”. And you’d be right to assume this is the wrong perspective to approach docker, because it leads to the problems you have faced.
Instead, try to think of docker containers as standalone applications. They don’t contain a kernel, they don’t have SSH, no Nano or VIM, just simply the Application, in a container, with enough supporting filesystem and OS libraries to make the application work.
That perspective is what helped me to get better at docker, I know it’s not exactly answering your question, but it might help.