I could use some advice, if you'd oblige.

So, here's the deal: My guild (I've been a part of it for almost a year now) has recently started raiding regularly. Over the past few months, I've been gearing up my character and raiding with them. We didn't start out with a lot of people interested in raiding, so we had pugs come in. Once when I went with them, we couldn't down a boss because of lack of dps. I was about in the middle dps-wise, so I decided to give up my spot in order for a pug with better gear to join instead. However, the guild has been growing. Last week when I was going to raid with them (I have much better gear now), there were too many people, so I gave up my spot once again. Now, this week, they've told me that their primary 10-man raid group has been filled so I can't go unless someone cancels. Now, this is a guild I've been a part of for a long time, and it kind of hurts that they'd leave me out (A few pugs joined the guild and filled in the extra spots) like this. It will be a while before a secondary group is formed and, well, I don't think it's really fair. I've been wanting to raid with them for a while, and I'm honestly not trying to sound like a whiny snot right now. Is there any way that I can get this across to my Guild Leader without sounding like a whiny snot? Oy, vey; this turned into a huge wall of text. Sorry guys :/ And please tell me if I have no case here. I want to know if I'm taking this too seriously.