I don't mind trying to help people out if I can. I'm semi retired and have a lot of time. It also helps me feel like my life is worth something if I can be a little help to someone else.
It is difficult to know what to say. For one thing, I don't really know you or your situation. The internet is good for communication in some ways but not so good in others. It definitely has its limitations.
In case you haven't thought about it, you might start by realizing there are different kinds of "friendships." I have friends that I've had for many, many years and I know they will be my friends as long as we live. However, there are other "friends" that come and go in life. My association with them is contingent on circumstances (where I work or live, for example). Then, of course, there is the category of "lovers," which is a whole other subject in itself.
One way to make friends is try and BE a friend to someone else. I don't know your situation but I wouldn't be surprised if there are potential friends all around you. What do they need? Can you, do you want to, help them in some way?
From what you've said, it sounds like you are an introvert -- that is, someone who doesn't open up or make friends easily. I'm like that myself and when I was your age I was PAINFULLY like that. I didn't trust people in general and kept my mouth shut. However, like you perhaps, this was very painful and I decided to begin changing. It took a few years but through various efforts on my part I began to open up more to people and *become* friendly toward others. This changed my life! I'm still an introvert, still shy around strangers, I'm still not very good at making 'small talk' BUT I do know how to listen to other people and, when it feels right, to 'be there' for them and let them 'be there' for me.
You're right, we all have secrets, things we're not willing or able to share with others. There's nothing wrong with that. There isn't anything "wrong" with you! You're a good person and have a good heart so let that be your guide. Little by little let yourself take a few risks with other people and learn from the experience. Of course not every experience is going to have a positive outcome but, regardless, you'll always lean something about yourself and about people, or at least certain types of people. Little by little we get better at being friends as well as finding them.
Hope this helps.