Your DoD rating was 80%, which represents the most you can get from the PEB. Likely you did not want to file a VARR to argue ratings associated with those conditions. Even if you did, you probably didn't want to delay separation or risk lowering your rating to do so. While your PEBLO was probably correct, I don't think there is an excuse for not letting you review everything with a lawyer first.
Your scenario is probably best dealt with after separation with the VA. Your fitting conditions, those not part of the DoD %, can't be argued about until after separation. The VA rating isn't official until after ETS, it takes about 2 months. You can submit evidence to them now to justify a rating change, the easiest way is through ebenefits. After the official ratings are decided the VA will send an official letter than should provide slightly more information about how they came to their rating %s. At that point you can file a NOD with the VA and begin the appeal process.
You are not required to have an attorney, but it may the best route. I personally recommend seeing a VSO first, as they will be free of charge. They don't have the same level of knowledge or the same requirements to look out for your interests, but they tend to get decent results in many cases.