I understand that you are discouraged. I can see why you sometimes get depressed. But suicide is a drastic and sad solution. There are avenues yet to explore.
The first thing I want you to do is read John Robison’s autobiography, Look Me in the Eye. I think his story will give you some comfort and perhaps also some ideas about how to go forward. Like you, he has Aspergers. And, like you, his particular gift is mechanical aptitude.
There are many companies that attract and value people with Aspergers. Computer firms, engineering firms, research labs, places that design video games, etc. are logical places for people with Aspergers and an interest in mechanical things or science to work. Some such places have so many people with Aspergers working for them that they become known as “Aspie-friendly.”
You’ve been very conscientious about looking for jobs. What you didn’t know how to do was look for work that fits your special talents in a place that will accomodate your special needs. For example: You say you would like to get involved in engineering equipment for people with disabilities. Have you thought about finding a company that does that? You might be able to convince such a place to try you out as an assistant or an apprentice. If you have trouble knowing what steps to take to identify possible job sites or how to approach them with this idea, it might be very helpful for you to find a counselor or an advocate to help you figure it out.
There are now many counselors who are experienced with helping people with Aspergers negotiate the NT (neurotypical) world. I encourage you to do a web search for counselors in your state who can help you. (I tried it out by searching “your state, Aspergers, counselors” and found several counselors who specialize in the issues you raised in your letter.) In addition, I found several web communities where people with Aspergers are helping each other. There is no reason for you to go it alone. Once you have the right help, I think you will find a way to make a living that you will enjoy.
In the meantime, if you get discouraged along the way and start to again think about suicide as your only way out, please do contact the National Suicide Prevention Lifeline at 1 800 273 TALK. There are people available 24/7 who can talk to you and give you some support during those difficult times.
I wish you well.