I hear your plea, and I can relate to your despair. Chronic pain does contribute to depression.
Firstly, take some action. Order some Palmitoylethanolamide (PEA) from Amazon. Take 400 mg. in the morning, midday, and bedtime. Also order some Topricin Fibro Cream from Amazon and use it whenever. Both are natural products which get me through the tough days (which are most days). The PEA will take about 3-4 weeks for you to feel a BIG difference, so don't give up on it. Will it work for Regional Pain Syndrome the way it does for peripheral neuropathy pain? I don't know. I have chemo-induced PN and it works for me.
There also is evidence that taking 2 grams/day (and not more) of a good Omega-3 fish oil can help with depression. Also available on Amazon.
Secondly, I am assuming that, if you believe in hell, then you believe in God. The thing about faith is trust in God. Perhaps your post here is God speaking to you… telling you to share your concerns with others. And the thing to remember about God is that s/he loves you and all her/his creations more than anything that we can imagine. I believe that with all my heart and mind. I personally don't believe that God allows bad things to happen to people, but God does help us get through our crises and afflictions. Ask for God's help. Keep asking.
Thirdly, and I'm speaking again for myself, it has helped for me to get out into the community and help others who are suffering more than I am… and really listening to them… making good use of the compassion we are acquiring from our own suffering.
And lastly, but certainly not least, a good psychologist or pain therapist is helpful. Ask your PCP or church minister for recommendations. Cognitive behavior therapy is very helpful, as well as meditation, controlled breathing, etc.
Realize that you are in a deep funk and be determined to climb out of that hole. Life is so precious… YOU are so precious.