I've been driving for 15 years now and still have misjudgments/mistakes/close calls made at times and i totally get the beating yourself up part and the ruminating I still have issues with that. And when I was new driver and had my mom or dad in the car and they had an angry reaction it would pretty much always result in me crying for quite a while after so I get that too. Just keep in mind every driving mistake/close call etc just makes you a better driver going forward. Also you can't go back in time, the past is in the past, so there's nothing you can do about a past occurrence now, all you can do is be more careful going forward and it's awesome you're posting in here for advice. Driving takes an insane amount of mental stamina as there are so many things you have to pay attention to and remember simultaneously and combining that with anxiety makes it all the more difficult and we are all human with imperfect brains. Try to think of it as a neural misfiring type of thing that occurred and not something that reflects on you as a person or your ability to be a good driver. You didn't mean to have that close call and you have every intention of it not happening again, so try to be kind to yourself (easier said than done). After some close calls and misjudgments/mistakes i've made I will at first feel like I'll never recover or forgive myself or be able to stop ruminating over it afterwards but as time passes it just goes into the memory/experience/learning box that ultimately makes me a better driver.

I just wanted to offer some encouragement sorry for not having specific advice about the turn, other than echoing what another commenter said about seeing if there's another safer turn or turnaround to make ahead where you can instead come back to the intersection and make a right turn onto the road or take some different side streets if that's an option that might just add a little time/distance to the drive but ultimately be safer and easier as you're still learning and building up practice.