Well.....if you're all by yourself....then that could be the reason......8) Or do you mean lonely in the fact that "no one understands you"....? Or lonely like you don't have a boyfriend type lonely....?
Your mind may be clouded right now with the cumulonimbus clouds of sadness.
Try going out with friends and families, whoever is/are close to your heart. Do something you're passionate about and enjoy such as dancing, singing, karate-ing and the sorts. Whatever, really.. Point is to get your mind off of thinking about the reason of being sad. Try and not isolate yourself too much as this may give you the tendency to linger on sad thoughts and the likes, stay around positive people. Sounds like a lot, but it'll be worth it once you get over being sad.
I suppose you can reach out to new people and start to build a relationship with each other or spend some time with your wonderful family and friends (reconnect with people you know already), get a hobby by being involved in activities you may enjoy, volunteer ( I think helping someone out can make you feel more better/connected to your life), and loneliness doesn't last forever because you're always surrounded by people who loves you.
well, i think if you got yourself a dog it would help you , you wont be lonely long!!!you will have to walk him and you will meet alot of other people walking their pets too. also, you will be saving a life if you rescue, only 1 in 10 dogs ever get ahome. 800 dogs are killed every hour. you will feel very fulfilled inside knowing you saved a live. a dog is mans best friend afterall! anyhow, hope you feel better soon. take care
Stop being alone. Or, develop hobbies and get busy so that you don't need people with you constantly. Independence from people is a valuable thing because if someday you don't have people, your life could still have meaning without them. I feel bad for the people who relied on people 100% for there happiness, and when they lost those people, they had nothing to do and an empty life.