I tend to be passive (as in non confrontational) with people I don't know well, though very "assertive" with people I do know well. I recently has a situation where I knew I had to say something hard to somebody I didn't know well. I didn't really want to say it but knew I had to.
What I did was write down the gist of what I needed to communicate. ran it by a friend who knew the situation and I could trust to tell me if I was being too blunt, subtle, or evasive in getting my message through (in your case I would ask if I was coming across as angry) to get objective help on delivering my message in the most useful terms.
It was short, but I typed it out, because it wasn't going to come naturally and I needed to practice or I'd bail on saying it, or it would come out too emotional when I got the nerve to say it.
If sending an email to communicate how you feel of course it is easier. If you want to talk to them in person, this might help more of course! If you are worried that you're being "sensitive" or whatever, it helps me at least to run it by a friend to make sure a more objective person doesn't think so (AND that also helps me realize if I am being reasonable and the other person tries to say I'm being "sensitive" to distract from the fact they are really just a rude dick)
Also, I find I get stressed if somebody doesn't get back to me about plans within X time, or tries to make things last minute. I have tried to start including things in emails about making plans like "If you want to do X activity, let me know by X time/day, and I will keep the time free until then." I have found some people really appreciate me knowing myself that well, and it has kept me from keeping time free waiting for something and then missing out on other plans.
It sounds like you really like them so if you tried that and they bailed last minute anyway- I would really just say something along the lines of "It seems like you like to be more spontaneous than I do, I like spending time with you, but I like to be free to make plans with other people. The ball is in your court if you want to hang out so let me know if you're free." Then just be busy if you are busy, either they will make the effort or they wont. Just coach your feelings in a non emotional way and leave it a practical thing about your time scheduling, and you wont be open to being told your emotions have anything to do with it.
I do want to say, your title talks about dealing with anger, but your post doesn't mention it, and only talks about being afraid of how the other person will perceive your behavior. I was curious if was mainly anger at their behavior, or if you were starting to get angry at yourself for not being able to be clear with this person about your boundaries, wants and needs.
Happiness will never come to those who fail to appreciate what they already have.
Last edited by Anneintherain; 06-26-2011 at 04:12 PM.