all thoughts welcome- can it stop?

I keep myself really busy. like so incredibly busy. and since starting to do so all the time in January I've felt better. and I didn't realize just how much business was a part of me until now it's summer and I can't stay as busy, and I'm depressed some days again. it's not all the time but the random depressive episodes are always lurking and I'm terrified of the next one every time. I've also been experiencing major anxiety. three of my best friends are moving away in a month and I fear loneliness more than anything. 

If I have a lot of really happy days, and I have good friends and a good home life, and I'm exercising and sleeping and mostly eating well and making sure I'm mostly regulated, I feel almost normal. happy. but the bad days always come around again. That's been the case since I was 10 years old.

I want to know- does it ever go away? can I make this stop? Yesterday was a really bad day and today feels like recovery for it and truly I don't want to live my life like this. But I still want to live my life. help, please