I'm sorry you're in so much pain. Whenever I have doubts, I go read the Bible. I know that sounds like false piety, but it's the truth. The Lord's Word always gets me through the day. Without Him, I would be totally lost.

I also try not to focus on what I don't have, and focus on what I do have. It can be as simple as nice weather or clothes to wear or a place to sleep at night. I thank the Lord for it daily.

It's easy to get lost in comparing ourselves to others - what we think is the perfect life. There's a reason not coveting what others have is one of the ten commandments after all. I'm certainly guilty of it. When I catch myself doing it, I immediately reverse my thinking by thanking the Lord. Over time I've found I do it less than I did in the past. There's definitely people out there with far less than me. I try to remember that.

I hope this helps you.