Hello Mr. Stanley Lio,
It sounds like you failed due to your lack of experience.
You are young and have plenty of time to learn. Of all the
things you mentioned the one thing I would suggest you
learn how to do is to draw schematic's and make your own
printed circuit boards. It won't cost you anything because
there is a lot of free software which will allow you to do
this. This web site
http://www.pcb-pool.com/html_uk/uk_service_1.htm has
everything you would ever need to get started. The below
schematic and PCB was done using the software provided in
the above web site. Good luck.
Regards,
Charles Bannister