It's not always the easiest thing to do. Letting someone inside your head and knowing your every thought is a scary thing to consider and not a simple task. Living a life of solitude may be what you prefer most, but is it the best? We are all human and nobody's life is going to be one hundred percent flawless. We have bumps and bridges we have to cross at times and when you do find a log in your path, it's nice to have someone there to help guide or comfort you.
I recently went on a sisterhood retreat for my sorority and having that weekend with my sisters taught me to be more open with letting others into my safety zone. You may think you are the only person struggling with hardships in life, but you will find there are plenty of people just like you that are going through the same thing and can really relate to you. I feel as if when people don't let others in, it causes them to bottle their feelings up inside and this can lead to depression possibly down the road. I've learned firsthand that it makes you feel better as well. When you let someone know your feelings that you truly trust and can count on, it makes you feel pretty good inside. I am not saying to go around and tell anyone and everyone your personal business, but find someone or a group that you can rely on and confide in and let it out to them.
You will start to become more confident in your daily lives. Life won't always be such a negative roller coaster for you. Your days will begin to brighten and your attitude will be uplifted. These can all happen by not being so closed off. People will begin to recognize your positive change and want to be around you more. They may even begin to open up to you. You will find life long friendships that way. I know I have found my people that I can always count on no matter what and that is because we both feel comfortable enough to share our deeper thoughts with one another. With family, it may be a little more difficult to share personal thoughts with, such as your parents. That is why I feel it is a good thing to find a close friend, that way you aren't bottling untold emotions inside. Like Meredith says in Grey's Anatomy, "I found my person." Go find yours and you will soon see why it is so important to let people in.