Sometimes when you lose or forget something - it doesn't matter what it is, it will probably upset you, bother you a lot and so it's stressing you out. Don't worry you're not on your own on this one, most people have this happen to them regularly or just on occasions.
If you want to try to make sense of why this happens to you and give losing or forgetting something a meaning. Think that maybe this has happened for a good reason.
If you drop a piece of food that has sugar, therefore lots of calories in it, this might annoy you if you were really looking forward to experiencing the taste of it, but perhaps it would have made you feel fat, so you wouldn't feel your gorgeous in your new outfit - so your self-esteem would get very low - never very nice.
A much more serious loss would be, if you smoke and you lose your last cigarette, you would feel gutted because you'd probably be craving one - but maybe that has happened because that cigarette was the one which started a form of cancer in your lungs, so you could have lost your life. So you not only would have lost your fag, but you could possibly have lost your life. if this happens to you or has happened, thank the heavens that you lost it. Hopefully it has made you want to give up, so you don't have the fear of losing your life because of having this habit in your life - so losing it turned out to be a good thing.
You should always try to find positive outcomes in annoying losing or forgetting things situations. Perhaps they can make you smile afterwards if you reflect on it or them.