I can understand feeling self-conscious about having a camera and using it "in public" but I doubt that most people are paying a lot of attention to the nature of what you are photographing with.
Well some will no doubt notice that you are using film, most likely most of those will have used film in the past, and will understand that your choice is just that - a choice.
If you are concerned about other's reactions, here is a test to try: Set your camera (medium format is most impressive) on a tripod and point it at something interesting. If people look interested, invite them to take a look through the viewfinder. I've had some really interesting discussions with strangers when I do this. And it has confirmed to me that people will appreciate what you do if you are clearly enthusiastic yourself.
By the way, if you want to get over feeling self conscious about taking photographs in public, IMHO the best cure is to do some work for a newspaper with a copy deadline and a liking for big "Art".