The conclusion is, that, whatever stance we do take, we have in ourselves implanted, the need for other humans. "The Lord God said, 'It is not good for the man to be alone. I will make a helper suitable for him.' " (Genesis 2:18) Be honest with your self, and think of all the times the "tfw no gf" thought crossed your mind. I've thought this thought all of the time. Think of all the times you've been sad because of this. I've tried to abolish this desire, thinking it was evil, but it was impossible to drive it out, because whatever I did, I always yearned for a woman. I always yearned for friendship. I thought that I was just attracted to the loud music at parties, the drinks, the way women reveal their bodies at them, but that was just one part of the coin. I yearned for another human being, and stupidly, I thought it was evil. So I let no one in, I didn't get attached to anyone. Beyond everything, I wished to be self sufficient. But below it all, the desire that wasn't satisfied kept me feeling sad.
Well, now I tell you, self sufficiency, at least for us living in the world, is a flat out lie. Luckily, we can change our poor habits. Depending on your age, you have different focuses in life. Some of us wish desperately for a girlfriend. Some wish for a child. Some simply want a friend by their side. And that is good - keep that desire.
What I'd advise, if you are in a similar spot, start small. First, start with your parents. Spend some time with them. They will appreciate it too. Then, you can go on to socialize more with friends you already know. Enjoy in their presence. There's nothing wrong about it. At church, try to talk to people before the service starts. A little chit chat before everyone focuses on prayer won't do harm. Next, talk to girls, in general. You probably don't have the confidence to "cold approach" a girl on the street, and that's fine. Sometimes, you can find that the pick-up artists are saying to not become only skillful with girls, but with people in general. That's what you're sort of trying to do here. From our parents, to siblings, to friends, all we are doing is to learn to discard our fear of connection, or rather, our unwillingness to connect. So it does take time, but gradually, there must be some sort of progress.
Keep in mind, this cannot become the alternative to our connection with God. In my view of things, God is someone we need spiritually, while we need people psychologically.
What if the one you loved so much leaves you? Don't despair. I believe that this need for love is instinctual (it doesn't bind to specific objects). Therefore, if you are truly hungry, any type of food will do. If your girlfriend left you, go hang out with your friends. With time, you'll forget about her. I don't have much to add, that was basically what I wanted to say. I just felt so crippled emotionally, and if anyone else feels like that too, I believe this might be the "cure".