Am I responsible for staying to training new hire?

So I’m dumb and gave my boss way too much lead time that I am leaving. It’s a very small business and I’ve been here 10 years so I thought I was being “nice”. He really appreciated the heads up as I work in a very rural area and we have struggled to get good help over the years. I had initially given this much time so I could help train the next employee as my job has a lot of tips and tricks cause the equipment can be tricky and the manufacturer no longer supports the equipment so I’m literally on my own for support. In my meeting announcing my departure he said he wanted me involved in the process if someone with my experience came up as I could “speak the language” to see if they would be a good fit. Well I gave the heads up in October and they are just now getting serious about hiring a new person. It’s become very uncomfortable in the office as they have kept everything extremely tight lipped about listing the position (didn’t want it listed publicly for some reason), the resumes coming in, and interviews so I’m very in the dark on if we even have any prospects. Is it bad of me to leave at the end of the year? I’m not wanting to wait around when I’m getting zero transparency on the process. I’m wanting to leave because right now, from what I’m feeling, I am in the transfer of duties phase as I’m heading out. Well since I am physically still here all this stuff is getting dumped on me to do. New BIG projects I’m not sure I can finish and also just feeling used as hell. I’m already burnt out hence why I am leaving and get paid 30k under the average for my position in my state. (I know I’m dumb and should have left years ago) but now I’m pissed I gave so much lead time. Can I leave at the end of the month or do I need to stay till March to train this nonexistent new person?