Take the time to cry and have a bad day. I fought tears for several days and felt horrible, but when I just accepted that I needed it and let it go, I felt a release. Then I have had some strong days, when I thought I could take it. Hang in there. I know it is hard to when they seem to be going on with life just fine, and we are suffering. But know you are not alone.

I was never a very religious person. I guess I believed in God but my parents had major differences in their beliefs which caused issues and so us kids weren't really raised with much religious background. Now I pray. I simply had to find something to offer me some comfort and relief. It works. I am still struggling to have faith that God wants what's best for me, that he wants me to be happy again, that I will have someone to give and get love from again. Faith is a struggle for me but I hope that God understands that. He created us to question didn't he?
I have also created a sort of mantra for myself. My prayers include asking God to help me have these things each day. I repeat my mantra to myself whenever I have a weak moment. I find that it helps me find my center and carry on. The mantra had changed and evolved a little over time as I find new things I need to work on but right now I ask for help with these things: Strength, Courage, Faith, Hope, Honor, Restraint, Trust, Grace, and Love. I do realize that some of them seem repetitive but each one has a special meaning for me.
Good Luck. I am with you, everyone here is. We WILL get through this.