unless someone has actually said something to make you think it's an (age thing) it may have nothing to do with your age...i'm in my 50's and have gone through the same things in some settings---sometimes groups have been together for a long time & they are just not real receptive to anyone new---doesn't matter if your 15 or 60...some of them will snub the new person- be friendly (pretend to accept) in the beginning- but then really not accept them into their little (click) don't take it personally & don't worry about your age...at some point you will find the right group for you- or with preserverence and time you will finally fit in (& hopefully not turn into) the 'group'. i stopped going to our local guild a number of years ago because although people were for the most part friendly enough---they were also at times quite rude---oooh & ahhh & comment on one person's show & tell- then not even look- talk among themselves-totally snub the next person's...age really was not a factor-
just keep on doing what you enjoy- show it off & try new groups, exposure...with time you will fit in like a glove when the right group realizes what a treasure you are! (our guild has memebers from 15 years old up to 80's+...they are rude to all ages equally)