Someone told me that I frequently make them feel uncomfortable and that it feels like I have a fixation with them. What do I do?

It could be the case that they're the only person who feels that way about and this is not general opinion. Or it could be that they're the only person honest enough to let you know. Sometimes we try too hard to win another person's approval and affections, and this comes across as intense. If this is the case, it is not your fault because that mean the people in your lives are not giving you the love and attention you need. Realize that you don't have to make everyone like you. People come in and out of your life and that's just a fact of life.

Try to understand what causes this feeling of fixation and causes them to be uncomfortable. Try to talk to them and understand why they think of you this way. If you're unable to talk try staying away from them for a while then return and see if anything has improved or become better. You could also try texting them or talking about this if you seem them around. If none of these work your best bet is to wait and see if it settles down and you can be on talking matter again. I wish you the best of luck.