“Good” and “Bad” Days of the Week

I have been struggling with my OCD only allowing me to buy things on Mondays. My OCD tells me that technically Sunday is the first day of the week which makes it perfect for buying things but it is not allowed because it is a sin to purchase anything on Sunday so it skips ahead to Monday as the best day. However; there is one caveat that if Monday is on a day of the week that has a 6 in it (except 16-Don’t ask me why) or the 13th it makes the day cursed and whatever I bought is imperfect. I recently purchased something I needed (a new phone) on a Tuesday because Monday was the 26th and “bad”. I figured it would work the same way as the Sunday rule and instead of the purchasing day being Monday it would just move to Tuesday. This instead backfired and has caused me extreme anxiety that I feel will never go away. The anxiety is nearly all day long to the point where I don’t even want to use my phone. Every time I even look at my phone or think about it the word “Tuesday” pops in my head and makes me very anxious. It has been a few days and I am still nearly the same and feel the urge to return it even though there is nothing wrong with it and order another one on a Monday causing me lots of hassle. I have been hoping that eventually the anxiety will go away but I feel unsure. My OCD tells me if you had just waited another week it would have been a “Good Monday” but you didn’t and ruined your phone making it imperfect. Does anyone have any advice on what to do or experienced something similar? Any help is highly appreciated.