Negative thoughts management

Yes.  That's taking a step towards positive thinking. It does help if you try and look for positives even in the most negative looking scenario.

Well, I don't know if I'd go so far as to say that everything happens for the best. I do believe, however, that everything happens for a reason. There are also many difficult experiences that can make us stronger. It ends up being something good in the long run, even though it may have started out as something bad. I guess that's the kind of thing you mean.