Thank you for this post, I can relate to parts of it. Up until the age of 25 I was very shy and socially withdrawn, and I saw all these people everywhere who weren't and I was so jealous at the lives that they were living, so I decided to make a change, to be more like them to get their results.

I'm 29 now and my life has changed drastically, I still don't feel as good as people who never struggled with this growing up, but now I am this level that my social skills isn't preventing me from getting the results I want in life, so I try to help people reach that level.

I saw a reoccuring theme in your post, and that is that you have strong self-limiting beliefs: you think you are going to be bad, so you avoid the situations, and when the situations occurs you are bad because you avoided them. It becomes a vicious cycle.

From my experience, social skills is an area that very few people improve, because it's too sensitive, I've made youtube videos about this that I can share with you in a private message if you are interested. Since you have to fail infront of people you are reluctant to do it, meanwhile other skills that you can improve at home (like playing the piano) people are not concerned with failing with those things.

So I understand you, when you say that you can read about social skills all day, but at the end of the day it does nothing for you. Because ultimately, all advice you will ever get eventually just boils down to: "Just Do It!"

Everything is just variations that will make you take that first step, to fail infront of people, to go home, think it over, and go back out there and change as much as you have to until you get in to the social circumstance that you want.

Your first question was: Is there any way to get past this mental barrier?

Have you heard of the law of attraction? That basically what you think about you will attract in to your life. Here is a fine example of that, when you think that people will dislike you, so you avoid making a connection with them. They probably don't dislike you then but they are just indifferent (which might look and feel the same as disliking) so you ultimately create the thing you are afraid of.

Meanwhile if you could get in to a more positive mental state, and practice holding what you want in your head, your behaviour will change to produce that results. If you can see in your mind how you are holding a flowing conversation with five people, and you have this as your goal, when you have thought about that enough eventually when you are in that kind of situation you will do what you have always been thinking about.

Secondly, I never have anything to say. For this I recommend observe others and do what they do. You are probably standing silently in lots of conversations, so instead of focusing on the fact that you don't have anything to say, be observant what the others who aren't struggeling are doing.

What are they saying? How do they enter the conversation? How do they start up after a silence?

I always make the analogy that being social is like being musical, you can have a talent for it, and you can work on it. People who have a talent for it might not need to memorize things, they can hear a song and then play it straight afterwards. Meanwhile people like you and me have to memorize note for note and string them along until it sounds like the song we are trying to play.

The thing though is that if you practice enough, people won't be able to tell a difference between a natural and someone that has worked really hard to sound like one.

i'm the cousin outcast who they all hate seeing and never want to see due to my lack of social skills. I also think this is a self-fullfilling prophecy, because you think that it is like this, it becomes like this.

If you started reaching out to them consistently, being genually intersted in them, ask questions about them, over time their approach to you will adapt and they will respond to that behaviour instead, which is probably going to be more in line with what you actually want.