Never felt what love is

So today I was out bursting with sad emotions, people love their partners hold hands with them and love spending time with each other. For me in my 25 yo existence never even had a close friend of opposite gender, i gather courage everyday to live life to the fullest but as the day ends there is this sadness, i have no cure for it don't have any answers but just living with it. Even when I'm eating the best food which I used to cherish some years back doesn't fascinate me, I have become a person who just longs for love but it's too far fetched thing, I don't socialize at all and I forgot on how to make bonds with people. I cannot do anything but living like this is becoming difficult for me, just wanted to vent out of what I was feeling today.