Edit to make it more visible: I work from home. I know how contagious and potentially dangerous covid is and I'm isolating myself while positive.

Currently in the bathtub "enjoying" a herbal medical bath to get me through the rest of the work day. I am sick. COVID. Coughing a lot, brain is fogged and my entire body hurts, especially my chest ugh. But at the same time I have a major project at work that still needs me to function a few more days until it's done. I KNOW I should call in sick for potentially the rest of the week but the thought of making life miserable for my colleagues (and probably them thinking I'm faking it/ being disappointed?)?! Why do I feel guilty over every little thing like that? It's not like I chose to get sick. It's not like I chose to run this project either. It's always the same too - I need to give 100% at work no matter how I feel and it's been like that since I joined the workforce. When I left my old job for a much better opportunity I cried because I felt so guilty. Anyone else knows this extreme feeling of guilt at work? And ANY advice how to overcome it? I know I'm not irreplaceable lol and my colleagues would be perfectly able to handle this project on their own but I feel like I'd let people down which is apparently not doable for my brain. Instead I chose to suppress my coughs and suffer while filling out excel sheets.

Edit: I work from home. I would never even consider leaving my house while positive.