Be lonely again

I was walking on campus when some boys and girls were playing together, laughing happily. Looking at their smiling faces, hearing sounds of laughter from them, I could feel that they were so young and great-hearted ,which moved me deeply. Just...because they were with each other playing happily and at the same time they were full of energy, and that was what I wanted to pursue,for I didn't have such happy and sweet time all the way. Really , I felt lonely...again...

I don't know why I am like this. All the way ,I am like this indeed...Does it mean that I will always be lonely in my future??? I am afraid...