I am sure that you're not a masochist of any kind, I have always thought that donors need to be special people to be willing to do this, even for someone who is a close friend.
I wouldn't think it's the kind of thing anyone would agree to do without a lot of thought. Even if you do only do it when it is badly needed your friend must be very special to you.
Don't most donors give to just the one Vampire? I thought that it was mostly that a donor would have one Vampire, but a Vampire may need to have more than one donor. Of course I could be wrong, but I am sure that's what I heard.
I spoke to one girl once who was a donor for her b/f, and she said that she had been approached before by someone else, but hadn't wanted to, but when her b/f told her he was a Sang Vamp she hadn't hesitated to offer. I asked her if it was the love she felt for him that she hadn't felt for the other person, and she said only partly. She said that the most important thing to her was trust, and although now the love gave her even more trust, that the trust had been there before the love. It was a two way thing she said. The trust she felt for him over this had given her the faith to love him, and the love she felt for him gave her even more trust, because she knew he would never hurt her, because he loved her too.
I thought that was amazing, it must take a lot of trust to donor for anyone, and they were some of the lucky ones. She found everything she needed in him, and he found everything he needed in her.
A true love story.

Ahh I'm a sucker for happy endings. lol
Is it something you think you'll ever get used to? I mean will it get easier over time or do you think it's something you'll nearly always have some trouble with?
It's a shame that sometimes when you tell them things like this people don't understand. How many of them do you think fail to hear you telling them about yourself, and completely by mistake hear you trying to make them become the same as you instead? There are lots of times when I have told someone something was a good idea for me and worked for me, and they have taken it totally the wrong way, and thought it was me telling them that it would be a good idea for them. They get really offended and nothing I can say can get them to hear what I really meant, calm down and understand that I wasn't saying they should do it too, only that it worked for me.

Or maybe I'm the only one this happens to.