I would say it is a mixture and we certainly get what we focus on.
When times are good we need to make the most of this and remember that bad times do pass even if we think they won't.
Life changes all the time x
I've been feeling alot like you about life but when I think positively it always helps and does get better.
I find it really hard being a single parent but then I was so unhappy with my little boys dad that anything is better than that !!