The two losses that affected me the most were my best high school friend, who died when I was a sophomore in college. The next year I met a girl who swept me off my feet and made an honest man out of me..... less than 3 years later, she died in a car wreck 6 months before our wedding.
One of the things that helped me the most was getting a kitten a week after my fiancee's funeral. I held on to that cat for 18 years until she died from chronic kidney disease complications a year ago. But while she was alive, she literally gave me something to live for.
I know this sounds cheesy, but another thing I did after my fiancee died was start playing guitar. Its amazing how much art that pain and loneliness can inspire, but it really did help me. I even asked a psychotherapist if she thought whether writing sad songs inspired by my late fiancee was a good idea. She said yes and so my homework began. After going through some manic phases in my life where I wrote more songs than normal, I am now stable on my meds and am sitting on over 150 original songs. The challenge has been making albums out of them. And although I think I've gotten over the hump of writing songs directly inspired by my former fiancee, I have been able to find inspiration in other places.
Not saying any of this will help any of you. Just sharing what worked for me and kept me alive, not to mention stays in half a dozen mental hospitals and psych meds and therapy. Oh yeah, and cannabis. That's helped a lot.