I need some serious help

I am 40 years old. I work as a freelancer sporadically. I spend a lot of time at home, especially the last 10 years or so. I used to be socially exposed much more till my late thirties. I am not married and live with my parents.I find it difficult to explain what is bothering me, especially because the English is not my native language. There are some people I have hard time dealing with. The funny thing is that they are very close to me. One of them is my neighbor , very close friend and something more so it is very difficult to avoid him. The others are my close cousins. Every day from the moment I wake up, I feel severe anxiety about him coming to my home. Sometimes I sleep as much as I can or spending some time in my bed, sometimes I drink alcohol... I strictly avoid to take some medicaments; I am not sure why I avoid them, but I do.My parents do not make my life easier, on the contrary they make it even harder. During the time I have became supersensitive.My threshold to any stimuli has gone way down.Everything bothers me: open doors, barking dogs, sound of the cars passing by, seeing people on the street from the inside etc. Every day let's say from 10 am to 10 pm I am kind of obsessed with the idea of him coming to my home and it is overwhelming. I can't stand it. I am unable to focus on anything, which is very bad when I have some job to do. I need some serious advice and help.