Angry emails

I am very frustrated tonight. I heard, from someone I trust, that some of the residents were unhappy about me spendind so much time in Regina because I wasn't contributing to call. I asked a colleague (someone in my year, whom I thought was my friend) if this were true. I suggested that anyone who was upset could share in the "Regina burden" (by this I meant the amount of time we are supposed to spend down here that I seem to be doing for everyone), and then they could do no call as well (NO ONE can say they like call). She wrote back and said that everyone was very unhappy and that she didn't see Regina as that good of an educational experience, and that not doing call was to my detriment and that I would come to regret it later (essentially insinuating that I would regret it because I couldn't pass my exams). She didn't think it was fair that they had to pick up my call.
I was very hurt by all of this. It was a very inflammatory email, and not something I would have done. However, in my infuriation, I wrote an email to our Program Director (copying her and my emails) discussing how I thought that this was based in no reality at all, that Regina has a lot to offer, and that my education has actually been enhanced by being here. I also said that if there was some real concern over my performance it was the first I had heard of it. Not to mention that my time in Regina was approved - by her!!
Once I had written the email and sent it, I then phoned her. I told her that I thought it was a much better educational experience for me to be in Regina and have people pick up my call, than it was for her when she took 6 months of Mat leave where we all picked up her call! What educational experience is there in that?! She tried to say how important call is, and I suggested that doing a Lap Chole at 4am was not important, nor educational.
I don't regret that email, nor the phone call. I regret that I copied it to the Head of the Department and the Academic Head here. I also regret that (because I am a nice person and felt guilty about the phone call, that I wrote her a second email later telling her that I was sorry if anything I said hurt her, that I saw her point (which was a lie) and that it wouldn't come between us (which it has). I thought I would be the bigger person and try to make amends. If someone had done that with me, I would at least reply. She hasn't.
I feel awful. Not because what I did was "bad", but because nothing was accomplished except making me feel worse. I feel like because I backed down, I look foolish.
It sucks that I was being the bigger, nicer person, and now I am the one who feels bad.
Should I have said nothing? Should I have let her get away with saying hurtful, untruths?
Should I really care?