Over the past year we lost 3/4 of our backroom TM's.
This leaves me aas the longest running TM there. Lucky I am also the trainer, heh.
The hardest part is the interim where you have crosstrained TM's taking BR shifts, especially in the early morning. You can expect more hours for sure, and it is not going to be easy to adapt in the short term. Long term though it's all up to your TL and HR to get people that will work out.
We have gone through many (seriously... MANY...) new hires and have retained about 4 very good ones. The rest are slowly being allowed to cycle out where we start a new hiring process. It takes time, but it's worth it in the long run. We are now starting to catch up again (we just went through another hiring cycle and got 3 new people, 2 are still here and 1 is outstanding) and every one is dependable. We even pulled 2 people from the floor into BR "full" time. Meaning they switched officially o the BR payscale and such.
We are now at a few vets, a few transfers from hardlines that are pretty good, about 4 good newer hires, a small handfull of crosstrained people that are good, and then some not as great newer hires. Some of them will leave soon. You can just tell.
However, we have a strong enough team to cover all the shifts, including the early shifts finally... a lot of thsoe who had left were early morning TM's.
It has taken 6 months to recover, and in the meantime we did not have an ETL. We do now, but running on a TL, 2 vets, a few good new hires, a lot of meh new people, and crosstrained was not great. Especially over Christmas. But we got it done and you will too. Just roll with it, man. Your leadership understands (or at least they SHOULD ;D) and you cannot be Superman. Just take it easy, do what you can, and most importantly.... do NOT let the shitty attitudes crop up among the remaining TM's. That stuff is infectious and never helps. The best way to keep it low is to not engage in it with others. You can be mad, frustrated, etc... but never contribute to a public bitching session back there. It only causes problems. We had a bit of that crop up and we had to keep it in check or we would have burned alive.
Best of luck to your store. It will get better.