First of all, dream big. I am dyslexic and I was able to get 660 and get into Cornell. If I can do that with the issues I faced with concentration and exhaustion it is definitely possible for others too, to get into good programs.
Secondly, a lot of Europeans prefer European MBAs over American ones because they believe that a one year program is more preferable to a two-year program as they find it too long. I believe than an American MBA cannot be compared to a European MBA and that it brings you so much more than what a European MBA can bring to you. The American economy is much more dynamic than the European economy and this also has a major impact on your career and job prospects.
Finally, I can only recommend that you use MBA Center services. I do not think that any teacher in the world could have been able to help a dyslexic person with ADD get a 660 in his GMAT and Dr. Hubert Silly has managed to do that for me and I can't thank him enough for that.