I'm currently playing in a hybrid MERP/Rolemaster campaign thats been going on for a while.
In the beginning, I was like you, feeling that I was useless with my crappy level 1 spells.
Like Rob mentioned, my GM kept telling me that I would become much more powerful compared to the other characters at the higher levels.
Now, I'm the first player to hit level 8, doing exactly what Rob suggested plus some.
I've helped turn battles with simple spells like Vibration I - make that crossbow in an enemies hand vibrate causing them to either drop it out of fear or causing it to misfire or fire with a penalty of some sort (GM's discretion of course)
Pick up support spell lists, like Lofty Bridge and use them to assist your party members to get to places they normally wouldn't be able to.
Don't focus on just 'combat kills' - you're a mage, think outside of the box!