Struggling with PTSD and Agoraphobia: Need Advice

OK here goes. I've been through a lot my whole life that I didn't deserve- trauma, mental and emotional abuse, manipulation. I finally got out of where I was but the effects of everything is hitting me hard and I'm experiencing symptoms of ptsd and agoraphobia pretty severely. there's important things I need and can only get in person but I've been off meds and am extremely terrified to go outside, barely can handle long enough to grab groceries and can only do so when its dark out, someone is with me and I can get quick easy access to the door but that's only sometimes I can manage so and its only getting worse. I'm afraid to be in public and fear running into those who put me through hell( they've done and do terrible things to other people as well, having no conscience). Even the windows have to be closed because of this. just the thought of having to even try to leave for any reason (though I will have to at some point) I get nauseous, headaches, overheat and have intense panic attacks. I don't know what to do or how to get through this, even though I have people with me who are protective, on my side and won't let anything happen to me its still not enough for me to be able to function like I wish or should be able to- the symptoms are only progressing. above all I'm afraid I'll continue to be stuck with this and I won't be able to move on or do better.