huge anxiety waiting for coursework results

I'm at uni in 2nd year and I really should be used to this by now, but every time I have to wait for results (summative and formative), I am SO on edge. I have always had really bad imposter syndrome (I'm talking like since I was six so it's always been like this in school too) and every time I'm waiting for results it's all I'm thinking about. I'll skip class to spend two hours on Blackboard refreshing grades pages *in case* the lecturer puts my mark up. It doesn't help that they don't tell us (most of the time) when the results are published, especially if the examinations are staggered like weekly presentations etc. One of my lecturers noticed this and put the grades up around 2-2.5 weeks after results, but I've been waiting a month for some of mine and it is terrifying me. I literally don't know what to do with myself if I don't get a first this year, as I want to make my chances as high as possible for finishing with a first as I already know that my summer exams will pull me down (I always underperform). I'm doing study abroad next year too so I really want to make a good impression. I'm so so sick of this and I have no idea how to just see how to get my results without sounding like some needy child all the time, but I cannot bear this wait. I haven't even started thinking about Christmas as all I want to do is get my results back and submit my January essays (I always submit before the holidays) but this is really hitting me hard. Does anyone have any advice?

ps. this was supposed to go onto the mental health forum but it kept saying this was a med school issue (??) so this was the closest I could get