Is there light at the end of the tunnel

Like most of you parents I am in the thick of it. The tantrums breaking things the appointments that feel like they're not helping at all. my daughter is five and things are just getting worse. I'm afraid for her future and I really want to know if there are any parents out there who have teenagers or adults where things have turned around for them drastically (in a positive way).

When did things start to take a turn for the better? Is there anything that you would change in the earlier years now that you're on the other side of it?

I just really need hope for the future because I'm so scared for her.