I doubt very much you are lazy or simply procrastinating. You do well in school in spite of a struggle to stay on task. Before deciding there are no therapists who can help, do talk to your school counselor or administrator to find out if they can refer you to a qualified counselor for an evaluation. You want to be sure to rule out depression before developing a self-help plan.
If the problem is ADD or ADHD, please take comfort in the fact that many, many brilliant people struggle with it. There is no magic formula or magic pill to deal with it. It takes determination. It takes being willing to learn how to work around it. But you can do it. Many of my most gifted students when I was teaching at University confided that they had ADD. But they learned to make it work for them.
If counselors are rare in your country, you will need to teach yourself. Do an internet search of “Working around ADHD”. I looked. There are a number of excellent articles online. In addition, search something like “Helping students with ADD”. There are a number of sites that provide teachers with ways to help their students. You can be your own “teacher” and use the tips you find on those sites.
You can also go to the “Find Help” tab on the PsychCentral homepage. Click on “Forums”. There you will find an online support group for those with ADHD.
I wish you well.