Contentment isn't just about relationships, even though they can be a big part of it.
Being alone can often be thought of as a bad thing or feel like a bad thing. It's something that you have to learn to adapt to, just like social situations. Some people might never get used to it and that's fine too. What you need to find is contentment in your everyday life. Just like you want to be in healthy relations with people, you need to have a healthy relationship with yourself. So you have to give and do special things for yourself. Even though I don't have many friends or family living in the same city as me, I still find ways to be happy by myself. I read books that make me feel fulfilled, I paint, I play piano, and I take long walks. I try my best to learn something new every week, sometimes I even take up a dreaded math book that brings me back to my school days. Learning makes me happy. Other times, just sitting on a park bench to watch and listen to the world can make me feel content. One of the most important things I think to do (whether you are alone or not) is journaling. Just letting thoughts sit in silence and linger alone, I tend to find is not a healthy thing. It's like sending an email or sharing an inside joke with a loved one.
Don't make being alone a thing to be guilty about, your mentality decides how you perceive things. The only thing that will come of negativity is negativity. Being kind to yourself and giving yourself room to breathe isn't a bad thing, it's a good thing. So get up every morning, breathe in and out. Make your life a life worth living.
You also have to know, that you can't be happy all the time. That's unattainable. I might sound like I have my life somewhat together, but everyone has hardships. I've lost and I've found contentment in my life. Not every day is a struggle but not every day is filled with happiness. There is no real solution or a step-by-step way to run your life. You just have to live it. In the end, it all comes down to what you did when you were alive and how you feel about it. Life is a bittersweet place.