Am I making this girl uncomfortable?

I am a guy who is normally anxious around women and most women won't even make eye contact with me let alone have a conversation except this one introverted girl in my office.

I would say I have a friendly relationship with this girl. We greet each other in the hallways and share a few laughs from time to time when having conversations. I am kinda into her but so far I have tried to keep it friendly.

But sometimes she would act anxious around me and even try to avoid me. I can't help but feel like I am making her uncomfortable because I feel like she can sense my anxiety and my interest in her. I also notice that she is not like this with other guys. She is very comfortable around them.

How do I assure her non-verbally that I won't do anything that would make her uncomfortable? Or should I just back off and leave her alone?