Making my alchemist/wizard feel more useful.

My group is playing Emerald Spire, which my GM has painstakingly transfered from 1e to 2e. We're all playing with the dual class rule. I have an alchemist/wizard and we just hit level 11. I'm starting to feel like I'm falling behind in terms of usefulness. I make elixirs/antidotes/antiplagues for my group every day, but I'm having trouble feeling useful during encounters. Our group has a lot of high spike damage, so my persistent damage doesn't really get to play out to it's full effect, as the targets tend to die relatively quickly. I'm starting to lean towards more support spells rather than damaging, as the Spire is chock full of hearty folks that tend to make all my saves. I am not a creative person, and as such, have trouble trying to find unique ways to help my party outside of really niche circumstances. Any help or advice would be greatly appreciated.

Edit: just for some context, our dual class "rule" is you can't have two martial classes. Didn't really apply to me, but it affected the rest of the party.