Maybe it is the Effexor that is making you feel more anxious. If so, increasing it will not help! You said most of the SSRI's you've tried have not been helpful to you. Maybe there's something else going on. Why don't you try going to a psychiatrist? They are specialists in diagnosing and prescribing meds for anxiety disorders. They should be able to determine why you are having this insomnia and creepy crawly feeling. I've found that internists are not the ones to discuss this with.
I hope you get some help soon. I have walked in your shoes---and it is not fun, especially when doctors don't take you seriously. A lack of sleep will only make this worse. Please see someone who will listen and help you before it gets out of control.
By the way, when I felt like this, I was in serious need of relief ASAP and my doctor did prescribe a benzo med to help immediately. I took it temporarily (and then he helped weaned me off of it) until the other med kicked in. It is not unreasonable for you to have a prescription for something that will help you NOW.