Hardy, everything you describe about your anxiety, sleeping habits etc are actually really common among people with certain pasts. Really really common. The thing is that many of us are trapped in a spiral, we are afraid to get help, because of the very things we need help dealing with. The only way to get out, it to step out, allow ourselves, even when it's scary, to open up to the possibility of healing. It's like having an infection or abcess lanced. We have to be willing to go through that first stab of pain to get relief, healing.
You will not be the only person there with fears and issues. You will not be a freak there, you will be one more person seeking help.
hugs