Problems with celica after splash guard removed

I have a 2000 toyota celica gts that is dropped to about 4 inches off the ground. I removed part of my splash guard a few months ago because it curled under after hitting a snow bank. Ever since then, whenever i drive it in the rain if i hit even a small puddle, the acceleration will become sluggish and eventually stall. When i try to start it back up, the starter will work but it wont ignite and turn on. After anywhere to 1 minute to 30 minutes, i am able to start it back up and drive, but the accleration will still be sluggish for a while.

Any ideas on what is actually happening? I know basically nothing about whats going on. I replaced the Air Filter with a Short Ram one and the problem continued to happen. I ordered a replacement splash guard and plan on putting it on this weekend, but i'm just worried about any damage i have already done to the car. I'm hoping that once i get the new splash guard installed the problem will go away, however ive noticed that the car has begun to run sluggish even when it's not raining. Any help would be appreciated. Thanks!