Just be patient i used to be going through the same thing wondering why it was taking so long for my first stripe. I've seen people with 5-6 stripes and not move up in belt then i've seen people with one stripe or even none move up in belt. Just don't let it get to you. often time it is if you haven't competed yet that might be needed to gain a stripe.
I have actually competed in an in house tournament. I competed against a 3 stripe White belt, and they put me against a 1 stripe blue belt as well, as there wasn't enough people present at the time to match up with me. Suffice to say i lost the tourny. But i did take both my opponents down, got side control and mounted. (Including the blue belt). I was up on points until getting caught at the end. So i thought within the next few classes i was going to get my stripe for competing and trying against both higher belts and larger guys. I guess i was wrong. This tourny was a little while ago, and i have probably been to 12 classes after that. In total i probably have been to 36 classes and one tournament and still no stripe
Mitsuyo Maeda - Carlos Gracie - Carlos Gracie Jr. - Marcio Feitosa - Tim Shears - Me.