Well, let's get that psychologist to tell us whether your son has a reading disability or just reading difficulty. Many kids have reading difficulties, and a good teacher or some extra tutoring can usually help get a student over this hurdle. However, most experts agree that a reading disability is a neurologically-based condition in which certain parts of the brain are responsible for making sense out of print material (letters, words, or sentences) or sounds (phonemes -- the sounds letters make). This condition (also known as dyslexia, with which you are familiar) is much more serious and requires specialized intervention. Since dyslexia tends to run in families, it is quite possible that your son has acquired the same kind of difficulty you have with reading. If the testing that was done in school did not answer this question, then ask that your son be seen by someone who can make that determination. You may need to have an independent evaluation done by a psychologist outside the school system. If you go this route, make sure the school will accept that person's findings as valid. Otherwise, they may just end up contesting the results, and that will be very frustrating for the teachers, for you, and for your child.
Your son is in a resource room for help in reading. If his teachers are working with him, thinking he has a reading difficulty and not a reading disability, they just may not be doing enough for him, or they may not be doing the right kind of intervention. That's why it's important to have the person who tested your son give you (and more importantly, his teachers!) a very clear understanding of the nature of his reading problem. The results of the evaluation should also be used to generate specific strategies for intervention. (A student who has a visual-perceptually based learning disability, for example, requires a much different kind of help than a child who has difficulty making sense of the sounds generated by letters or letter combinations.)
The private tutoring that your son gets after school should be related to and reinforce the teaching that takes place at school. This means that the people at the school have to talk to the private tutor.
What about the ADHD issue? I think your pediatrician and the school psychologist need to have a professional discussion about this diagnosis and come to some agreement. If they can't work this out together, then ask for a third, impartial opinion. Since there are specialized interventions for ADHD (behavior contracts, instruction in self-monitoring, medication, etc.) this issue needs to be resolved. Ideally, they should all see themselves as players on the same team. If you think this isn't happening, you should request a meeting of all the professionals so that they will both be "on the same page" regarding your son. If you don't think they can work it out, bring an advocate or an independent clinical psychologist to help you make sure the meeting stays on track and that it results in some agreement.