That creepy-crawly sensation in the legs is something I experience as well. Feels like ants crawling or tiny electrical shocks running up and down my legs. This is separate from the extreme leg pain, and can happen in the day time as well as at night. I have found that a TENS machine can disrupt this crawly sensation, and sometimes will eliminate it completely, but the TENS doesn't help with the actual leg pain. I always recommend that a person try a TENS machine because you never know what it might do for you. For some it ends pain.
@Nan , do not despair. I found that the only really useful antidote to despair is knowledge. The best thing you can do for that is to continue to try different things, approaching it with the attitude of a scientist doing experimentation. This gives you something to focus on and may result in your finding something that helps.
When it comes to depression, sometimes it is necessary to see a therapist and get suggestions for how to manage that, and in some cases medication is a good idea, even if it is just temporary. Medication, if you get the right one, can take you enough out of the darkness that you can lift your head up and start to take some action.
Another thing that helps is to do something constructive. It can be literally anything. Dust the house, organize a drawer, do 10 minutes (or five, or one) of yard work or exercise, draw something, anything will do. Then, praise yourself to the skies for having accomplished that. I mean, really tell yourself what a good job you did, as if you were praising a child for cleaning her room. Accomplishing one thing and giving yourself a lot of credit for it really can help.