This is very like certain manic behaviour
s.
"Is she aware that her behavior is erratic and confusing?" If it is a product of full mania, usually not at the time. People acting like this are not being rational so giving any creedance to their statements is not really appropriate. Frequently they are driven by the latest sensory input, or some expansive fantasy that no rational human being can keep up with. And in her eyes everyone will seem to be slow and keep her from achieving her vision. The sensation of this type of mania is frequently of high emotional elation being frustrated by what is in fact "mundane" reality.
"How should I have handled this situation? "With respect to her, if it is happening the solution is treatment not discussion - that is it is a doctor's role. So, there is no point in trying to convience them you are "not draining their energy" or anything else because it is not based on fact but on distorted reality. With respect to you, don't base your opinion of you on anyone else's opinion. Test yourself instead - healthy, children, if let try to findout and improve their abilities - they don't ask others. So, find out and develop your strengths don't base it on others opinions. Her opinion in this circumstances is typical - she is following her muse and anything, even just making a phone call, that is not directed towards here goal is intensly frustrating and draining. So as you can see there is nothing you can do to keep up with such thinking.
"What should I do if she ever decides to try to be friends with me again?" You don't have to be friends with her. If you are, then recognise that such a relationship is unreliable, not necessarilly due to her at her best, but given her condition and inadequate treatment. I have such a friend, their company can be very enjoyable, but I have other friends who provide me with reliability.
"I cannot be friends with her again after all of this - but how can I communicate this to her in a way that is productive for both of us?"
It is important for her to realise that her condition, which may seem to her not to be a problem given she may feel energised and high, has a price. Only in this way will she get adequate treatment if possible. I would simply point out her behaviour
and how while you understand it may well be due to her condition, you cannot afford to continue dealing with her problem given yourown medical condition and given your need for consistancy in friendship, which is normal and yet is not being fulfilled in this relationship. Wish her the best and simply don't resent for your sake - simply accept it as part of learning about
the diversity of human experience which will help you as you deal with the many wounded humans thatg live on this planet. In this way you will feel that the time spent on this relationship wsn't waisted but had just run its course.
"Sorry my post is so long." - It isn't. You have brought up an important topic. It will allow others who may need to understand the price of this illness on theirs or on others lives, and motivate them to seek help.
Best of luck.
PS. I've Crohn's so I sympathise with your condition.