advice please - shielding

Hi - very new to this. Had a diagnosis back end of last year, started meds in March (perfect timing!) and then more meds in the summer. The combo means that I have been told to shield this time around. My problem is with my partner - he is, i think, struggling with my diagnosis and what it means - i look relatively young and healthy and he just doesn't seem to grasp that the meds I am on are serious, that the diagnosis is serious or that I have to shield (which means no, sweetie, I'm not going to go out to get a coffee in the local town) because the possible consequences of exposure are very serious. Does anyone have any advice on how to make this sink in, without lecturing/ranting - which I fear I am otherwise about to start doing! Thanks!