Unsure as to what I'm feeling for my best friend

So I (22M) known my friend for about 5 years now and only gotten really close in the last 2 years, we do so many things together and she's my best friend, the only thing is I think I'm catching feelings for her. She has had a boyfriend for 1 year before she even knew me and they still seem like a very stable couple who got their stuff together, I'm not the type of person to meddle with others relationships hence why I never tried something in the beginning of knowing her eventho she's my exact type the feelings got blocked by this pretty hard, so we easily became friends and didn't think to much of it. But she's giving such weird signals (or I misinterpreted them which is most likely,) Her presence is just lovely and I feel re energized being with her and when she's not around I feel drained kind of like a crash after a big high. but now I somehow got a bit of hope that she's the perfect fit for me and we emotionally match. I'm kind of lost on what to do or what I'm feeling even is true love I can't seem to take my mind off of her and days go by and I'm totally unable to enjoy my daily life after we meet

I'm scared as to what to do, confessing my feelings to her doesn't feel like an option, again I don't want to meddle with others relationship and I know her boyfriend by now, and it only seems like a lose/lose situation I won't get to be with her, and can only make things worse by confessing and possibly making it weird, I don't want to lose my best friend and the great times/fun we have together.

Kind of a long vent, and unsure what it is I'm actually feeling, someone said it might be limerence? any help would be appreciated!