A fact of life is that at some point or another, we will always come across someone who not only rubs us the wrong way, makes us angry, or even makes our blood boil at the sight of them. While I'm not saying you're being immature, I can completely relate to your situation.
Where I presently work, I had a supervisor who hated me. I'd like to think that I just annoyed her, but I found out that she did indeed hate me and wanted to make my life here a living Hell. She succeeded. Not only did she make my life a living Hell at work, but she also played favorites with someone on our team and gave her all the promotions/special projects/etc. I grew to hate both her and my supervisor. Seeing them made me sick to my stomach. Being around them made me incredibly nervous because I knew that anything I did (whether it was good or bad) they'd hold it against me.
Eventually, I found that I had a skill which neither of them possessed. I had programming skills. Her friend couldn't duplicate what I did, so I was no longer her competition. My supervisor desperately needed me to create programs for our department, and there was no one else available to do this task. Suddenly, I had the upper hand. From time to time, her friend would get snotty with me and demand I do certain things for her, but eventually that stopped. THEY needed ME. They went from snotty horrible people, to calm and meek little kitty cats.
I eventually got moved to another department placed under a different supervisor where my skills can be better matched, and my project adequately followed. I rarely deal with either one of those women anymore, and I don't get as anxious around them.
Now, I realize that you probably won't be as fortunate as I am. However, that 3 paragraph journey I described above was a 4 year reality for me. I had a range of emotions from trying to ruin them socially, to wanting to kill myself, the list goes on and on.
I found that what helped me the most during that time was when I would feel mad/angry/upset with them, I would write down what I wanted to say to them (or sometimes do to them) on a piece of paper. I would then discard that paper securely. To keep it even more discreet, instead of writing out full sentences and let them be in plain view for whoever was to walk by, I would write my thoughts and feelings by placing the letters one on top of the other so that it just looked like one big inky mess.
Writing about my frustrations as I was going through that moment of anger/ frustration really helped me. If that didn't do it, then I would go to a quiet place (like my car or a bathroom stall) and write a text message to a good friend, or someone I love and trust. I would go nuts with all the thoughts I had and how I felt, etc etc. I wouldn't send the text though because like you, my friends and family grew tired of hearing my rantings.
Other options you have are:
1. Quitting your job
2. Asking to be transferred to another dept/building
3. Talking to the person about why they bother you and establish boundaries
- Be more specific with them than just telling them you want to keep it professional. If you can say to them, "Look, I'm glad I was able to help you find a job, but truthfully, over this time of getting to know you, I'm finding that our personalities just aren't compatible. I can't be friends with you at work, or anywhere else. I'm sorry if this offends you, but if you could please leave me alone, that would be best for the both of us."
(Yes, I realize that's harsh and super rude. But would you rather be rude and be left alone, or nice and be bothered constantly by this person?)
When someone does something "wrong" to us, we feel like they "owe" us something. It sounds like you feel as though she took advantage of you so as to get a job. While we don't know for sure if that is true, you feel betrayed, and for some reason you've let this feeling of annoyance with her grow into something that's out of control. If you can visualize that "debt" of an apology she "owes" you, and without her apologizing to you, release her from that "debt", maybe you'll feel better.
Can you explain why you just can't seem to let go about your feelings of dislike towards this person?