How do you explain your behavior without dismissing having made someone else uncomfortable?

I (F20’s) have a co-worker I keep running into. I can tell that they’re now uncomfortable seeing me, as it just keeps happening…  We work at the same office, but not in the same department. At this point, they seem to think I do it on purpose, as I’m not able to be subtle about how awkward it makes me feel, while I try my best to ignore them. 

I’m autistic and I struggle with social anxiety. In usually try to block out people around me, to avoid becoming too anxious. But sometimes I become hyperaware of a person in my surroundings. If I can sense I’m being perceived, I panic, I fidget, I become awkward and too… hyperaware. And it is not subtle. At all. I can tell others notice it happening. I can tell it makes them uncomfortable. Which in turn makes my awkwardness worse. 

I try to accept that most people will inevitably think some of my behaviors seems “off”. If I sense someone’s already made up their mind about me, I try to let it go and avoid letting it influence my choices. And 99% of the time, the weirdness eventually passes, if I just keep doing what I usually do. At some point we reach some unspoken mutual agreement of just existing in the same space. 

But it hasn’t gotten any better and it’s been months. Ignoring them clearly doesn’t work. And they appear increasingly uncomfortable. I’m afraid that the reason is because I used to have a small cr.ush on them months ago, they somehow might have noticed? And while it quickly fizzled out, they wouldn’t know. I think it made the run-ins go from uncomfortable coincidences to seemingly intentional creepiness, which I hadn’t accounted for when I decided to just to stick to my “routines”, even if it meant occasionally passing by each other.  

I notice some microaggressions from colleagues from my co-worker’s department. While it’s subtle, and easily fall within the category of plausible deniability, it still affects me. I’ve heard people comment on my presence. I have heard “subtle” remarks trying to gauge my reaction as they walk by… 

I try to ignore it and wait for it to pass. I try to look busy and focus on my work. But at this point the thought of going to work is making me anxious. I don’t believe it would be fair for me, to blame others for misinterpreting my behavior, as I know it doesn’t fit the standard of normal behavior. But it hurts so deeply to constantly feel misunderstood. I feel awful and embarrassed about making someone uncomfortable. But I’m scared of coming off as dismissive, or as if I’m using my autism as an excuse, if I try to explain myself. 

How do I explain myself without seeming like I’m dismissing their discomfort? Should I write it down or would it be better in person? I don’t want to risk making them more uncomfortable :( 
Is it possible to do in a way where I can avoid sharing my autism-diagnosis with everyone at our office?