How to know it's really time to transfer?

Spoiler: I already know. I’m pretty set in this decision but I would still like to know some outsiders’ opinions.
For one, I chose this school for all the wrong reasons. Despite being pretty dependent on my parents in high school, I still thought going away for college would make me seem “cool” and different from all the kids that I thought were “stuck” in our hometown. Mistake number one. Secondly, I thought going to such a prestigious university would make my parents proud, but now I’m just undoing it all by being absolutely miserable here.
I’m not getting the grades that I should be. And there are a lot of reasons (not to be confused with excuses) for this. I was diagnosed with severe anxiety and mild depression two weeks into coming here – things that probably always existed but just hearing someone say it out loud and having to face it 100% alone here has been tearing me apart.
Also, being that I am far from home, I know no one here. Even now, three months into the school year. I have not made a single friend or even acquaintance since being here, and no, I’m not exaggerating. I try to be friendly and say hi in the halls, but I’m greeted back with dirty looks always. Is there something wrong with me?
Lastly, I spend a lot of time in my room. It’s hard for a person like me to get out there when I have no one to explore and discover new things with. I feel cripplingly alone here and feel that I would be better off at another school where I at least have some friends to get me started instead of here, where I have nothing. I have gotten nothing towards my major due to the advising here and won’t be losing anything if I leave. I feel like if I tried to stick it out one more semester, I would probably drop out due to how bleak things are here.
What are your thoughts and/or any advice you have on the transferring process? How can I effectively convey this information to my parents, whom I know will be disappointed? Thanks for reading

Have you been going to the campus counseling center regularly? Have you engaged in any clubs? Do you have a campus job in the bookstore or dining hall? Are you volunteering with any groups on campus? Have you checked out what the campus ministry has to offer? You can’t explore things with people if you don’t make efforts to interact with people. All the things I suggested tend to be non-judgmental and accepting. Spending a lot of time in your dorm room with the door closed isn’t helpful. I just don’t believe that every time you say hello to someone you are given dirty looks. What possible reason would there be for anyone to do that? Your perception of how others react to you is magnified by your feelings of loneliness.

Read this please: http://talk.qa.collegeconfidential.com/college-life/2016222-to-those-who-feel-lonely-homesick-friendless-think-they-chose-the-wrong-school-etc.html#latest
I wrote it after my daughter had an awful time as a freshman, five hours from home, and knew absolutely no one. She too thought about transferring. I know of at least three other parents here on CC whose children had similar experiences. They managed to stick it out because they had to get through it.

I don’t think transferring is going to cure your problems. If you have anxiety and depression, you have to continue to get counseling. Your friends at other universities will be there, but bear in mind that they have moved on too, and probably have new friends. Don’t expect that things will be like they were in high school. Don’t run from your current college expecting that your troubles will be magically resolved. You may just encounter a whole new set of troubles.

You also need to talk with your parents and an academic advisor at whatever new school you plan to transfer to. Can your parents afford another school? Will any of your credits transfer? You have practical considerations too.