I'll add to this since I am an introvert, but I also have Claustrophobia and Anthropophobia on a more mild level. It doesn't keep me locked up in a house like Agoraphobia.
A) I do need money so I have a job where I go into an office and play around on networks all day and have very little interaction with my coworkers face to face. We use MS Lync, mostly, to communicate. Its use makes it VERY easy for me to talk to people.
B) Who needs a mate? opposite sex is nothing, but a problem. However, I've realized that I am more of the problem in a relationship so I stay away rather than get my heart ripped out every couple years.
C) If I need to go to the store to shop for food then I usually work up the courage and go late at night when the crowds are minimal OR I go with one of my roommates and they pretty much act as a 'handler' or distraction to everything else that is going on. That way the crowds of people at the store aren't so bad. For clothing and most everything else I need I can buy online and have delivered right to my door.
Also I'd like to know what survey you did that paid you 50$. The last time I took a survey was about a decade ago and they were only going to pay me 3$. I asked for 5$ so I could actually buy lunch and they walked away. Cheap bastards! Last time I remember getting 50$ for other than an hour worth of work was when I donated plasma. Twice a week and get 30$ for the first visit and 20$ for the second visit.