Shining, so sorry you have to deal with this right now. Yes, I’ve been at jobs when I had nothing to do and bored for some time and then I had to work over time because all of a sudden there was a lot of work. I was a consultant, so I was used to work like that. I completely understand what you are feeling. I was on the project when H dropped the B on me. I was in the fog, grieving, trying to make sense of it trying to function. I didn’t tell anybody about my sitch for some time, because I was afraid that they would just let me go. Luckily, I was still able to do what I needed to do for my work.
It sounds like your boss is trying to use the situation to replace you with a less expensive candidate. I don’t know if he can just fire you for the reasons he stated. I don’t even know what to suggest in this situation, except to start looking for a different place to work. I know how hard it is right now, but I believe you can do it.
M:50 H:52 S28 (my S from previous marriage) M:17 + 3 BD: 06/12 S: 06/12 - H works in another state