I’m 19 I've been alone for so long that I can't even communicate with anyone. Not even simply general loneliness; I've never been in a romantic relationship. I don't even have friends.

II've been alone for so long that I can't even communicate. Loneliness in general, not just romantic loneliness (I've never been in love).

I seldom ever manage to construct a complete sentence when I do have the chance to speak with someone. Girls are unimportant. Stutter, stutter, and then some more. It is so tough for me to actually communicate what I have in mind, even when I do. Who on earth has the patience?

I'm so overcome with fear that I'm unable to even leave the house or communicate with anyone online. Although I'll occasionally comment, I can't genuinely engage in a discussion or develop any sort of friendship or relationship. 
I've tried all the available online dating services. I get the numbers, but after that, they just disappear. I return home alone and consider ending it immediately after observing couples holding hands, snuggling, and other romantic gestures makes me envy them knowing that will never happen to me.