Glad I could help!
As for the scoped aim throwing you off, it could be that you’re accustomed to the way Ashe shoots, and that you’re unconsciously aiming the same way you would on Ashe. I actually have the opposite problem where my time on Widowmaker makes it hard for me to learn how to properly aim with Ashe.
On days when my aim feels off, I run through a mental checklist to sort of troubleshoot my aim, like the way my arm is positioned, if my mouse is centered, if my latency is stable, and if I accidentally bumped up my dpi on my mouse. 85% of the time it’s one of those culprits. However, sometimes it’s a small thing like just needing to take a break or getting something to eat so I can come back refreshed. Widowmaker, like most aim intensive heroes, can be fatiguing to play for hours on end—-moreso I would say than any other hero. She can be inconsistent for that reason even for people who have invested hundreds of hours playing her, and that’s sort of part of the whole package of playing her. By taking care of yourself and not overthinking your problems, you’re doing yourself a huge favor when playing her.
As for the reticle thing, one thing that helped me that might help you is changing the opacity on your reticle. Oftentimes I would get really distracted and stare at my crosshair instead of the target, which caused me to whiff a lot. Some would recommend just completely playing without a reticle, but I think that’s way too much of an over adjustment for a small problem. I play with a size 3 green dot, 45% dot opacity, and 75% outline opacity. This makes me focus more on my target, but if I need to re-center I still have a reticle on my screen to help me readjust.
Now the aim anxiety thing. It is very, very real on Widowmaker. It made the first 20 hours or so of learning her absolute hell for me. I kind of got over this by playing in ffa deathmatch and widowmaker headshot lobbies. You said aim isn’t your issue, but anxiety might be. By putting yourself repeatedly in high pressure, fast paced situations like you’ll see in ffa and headshot lobbies, you sort of get accustomed to high pressure situations, with the bonus of learning how to deal with characters in 1v1 scenarios you’ll often encounter in comp. I can’t stress how much this helped me with my anxiety on Widowmaker. I did get my stomped a lot at first, but eventually you stop caring, calm down, and focus on your own improvement instead of winning—which is really the goal here.
Going off the above tangent for aim anxiety I also highly recommend shooting bots in the practice range just to get your aim warmed up. Giving your brain something fairly mindless to do is a good way to get in your groove before playing.
I think that’s all I have for you now in regards to the things you’ve talked about. I would recommend watching widowmaker VOD reviews if you want a more in depth understanding of positioning and gamesense, but other than that everything with her comes with experience and practice.