Well just because You never hear someone say "I like You" or something similar which pretty much means the same it doesn't mean that nobody does, or that nobody could. For example, apart from after i've spent some time helping someone and might get a "Thanks" for it, which happens surprisingly seldom actually, i pretty much never get to hear (or read) that i'm liked for any reason. When we got the chat-room up here it apparently became less of a hassle to thank someone (since i've noticed that feelings for others are expressed much more freely in there for some reason), so if You feel like You're not needed, perhaps You could start helping others in some way in the chat, and i'm sure You'd feel alot more useful.
When it comes to real life, i can't even remember the last time that someone implied that they like me in some way. People seem to be much more careful with what they say in real life than, for example, in a chat-room, and alot of people in todays society actually has big problems with expressing their feelings in a healthy way, which probably is a big factor in Your case too. People also expect so much from others these days, so to actually being able to "officially" say that You're helpful (which is one of the easiest ways to become fond of others) it often takes alot more work than we think.
For what it's worth; i talk to so many people at this community alone that i have a hard time remembering whom i've talked about what with and so on, but my feelings never fool me, and for some reason i get glad when i see Your username. =) I just remember something positive about You from somewhere (the chat i think it was), and that's all i need to remember right now.