I live in computerland a lot of the time.
Maybe I can relate.
Don't feel bad about the canned replies.
You'll get a larger repitoire as your get older and develop it, they'll start sounding more natural the more you use the, and eventually you'll have the makings of just about any conversation you end up in.
At least, that's how it went for me.
Aside from that: confidence is key.
Just reply to people, say what you think, don't worry too much about it.
If you're smart, and sound confident, people will listen, even if it's total BS that you just came up with.
I'd be happy to talk to/chat with you any time, just drop me a message.