Depressed?!?

I’ve recently come to terms with the fact that I may be fighting depression. Anyone else suffer depression in your mid 30s without a history of it? Yes, I did suffer a close loss over a yr ago and that seems to be when it started. I think about her a lot... daily usually! She was my youngest of two rescues I raised solo since I was in my early 20s... since her passing my surviving older dog has also been showing signs of depression. Sleeping all day. No real interest in anything 🤷🏽‍♀️. Can’t tell if I should wait this out or start researching treatment options?!