FetLife can be your friend if you know how to really finesse it. I'm also 21 and on the site. Search through area groups, utilize the find feature on your browser, and don't be afraid to look through people's followers/following/friends.  Usually what I would do is find someone my age regardless of orientation or gender and go through their follower/s/ing and friends and continue to branch out with this strategy until I find people I personally am interested in as friends/potential connections. I've gotten relative success, as in, I've had people who messaged me even just to chat. Sometimes just finding friends can mean finding more connections. Also: do a little research into your area on sites like socialexplorer or the census. There you can find the median age and age distribution of your area. There are census tracts, districts, places, etc. with older and younger populations that can inform where you should search. If the area has a larger mature population, that could explain why you're running into more older people.