I understand why people would assume you were contagious. Covid has been so invisible—so ANY manifestation is grabbed onto and declared “proof of infection”. The problem is that there IS no way of intuiting whether someone is contagious at all. The bigger issue for you is that having Long Covid and having an active Covid infection are like comparing apples and ….Ferris wheels! No one is in any danger because you/when you feel horrible. This is very much like other serious cell-based illnesses— like cancer, for example. You cannot catch breast cancer by being near someone with breast cancer. You may want to (?) use this analogy with your craft group or church leaders. Like cancer, there is nothing they can do —EXCEPT acknowledge how awful it is and cut you enormous slack for failing to attend, forgetting to notify, being too tired to bring snax when it’s your turn, etc.
I hope this helps.