Lost Muscle/Strength Recently

I went on a mountaineering trip. There was a long time where we faced near death and made an emergency descent with minimal food consumption where I definitely pushed myself to physical limits. I think this especially made me lose some weight, along with the generally long day of trekking and week of hiking before that and my #s for bench ME and shoulders so far have gone down.

I’m wondering how temporary/permanent this is, and tips to speed up getting back up there.