Arriving earlier than usual is important because it will allow time for your accomodations. In addition, it will help incase there are some delays while going through security.
Most airports have "Airport Escorts" and they are free of charge. These escorts will help you through the security line and may help you get to your boarding area.
it's really important to be honest and up front about all the things you are carrying through security. TSA Officers will try their best to accomodate you, but keep in mind not all officers are the same.
If you're a frequent traveler, you should consider purchasing the TSA Pre✓®. The TSA Precheck will help you save time becaus you won't have to remove your shoes, laptops, liquids, belts, and light jackets. Over 180 airports and 30 airlines offer the TSA Pre✓®.
Allowing extra time is important when traveling because you cannot predict what delays may occur and certain airports are huge. In addition, it may take longer than necessary to unload at certain airports.
Make sure to be prepared to board first, as airlines typically will board people who take longer to board (such as disabled travelers) first.
If an airport or airline tries to force an accomodation, you are not required to accept it. In addition, it is important to know your rights. Feel free to read more information here: http://www.friendshipcircle.org/blog/2012/06/05/air-travelers-with-disabilities-here-are-your-rights/