...I feel like I'm being punished for something I can't control. (This may get long, and a bit TMI, I'm warning you now...)

Ever since I was 7, I've been going swimming on Friday nights with my two best friends (they're twins), my sister, my dad, and my friends' mum. When I started my periods aged 13, they were all fine for us to do something else like go to the cinema once a month, because I couldn't use tampons so couldn't go swimming. I still can't - I don't know why, but I've tried many times. For a while dad went through a phase of asking practically every week if I'd tried using them again, and I'd have to say I tried, but I couldn't...I was frustrated, and felt guilty at stopping everyone going swimming once a month. It felt like my fault - even though I couldn't control it, I should be able to. But then dad stopped asking, and the rest of them all seemed ok with missing out on swimming once a month...sometimes it was less often than that, if it started on a Saturday. But then my friends and their mum started going swimming anyway, even when I couldn't. My dad and my sister did something else with me for a while, but the past few weeks they've gone with my friends, leaving me at home. Fair enough, I guess...after all, it's definitely not their fault, and it's unfair of me to stop them doing something they enjoy just because I can't do it. There's more of them than there are of me - I'm outvoted. But still, it makes me feel lonely...and, like I said, like I'm being punished for something I have no control over.

Have they just been putting up with me all these years? Do they really want to see my sister, not me? Does it make any difference that I'm not there?

Ugh, I hate when I start thinking like this. I'm not sure if I should post this, but I'm going to anyway, before I make things worse for myself.

I'm such a loser.