Something once happened to me that I thought may be the worst thing EVER. It turns out that it was [not THE best but] one of the BEST things that ever happened to me.
Something else happened that at the time I was SURE that this is about the best thing possible. As good as I thought it would be - it was that bad.
Another thing happened that was GREAATT for a long time but when it was over then it HURT [and still does].
The message:
A] Don't worry. We NEVER know how things will work out and worrying never helps.
B] Let Hashem run the show. We have little control. All we can control are our feelings and to a certain extent, our actions. The results and outcomes are completely in His hands. Let go and let G-d.
C] Nothing lasts forever. [Except Hashem, your neshama and maasim tovim].