Sounds like your timing might be off. I'd say to check the belt tension, and see if your timing belt is stretched at all.
Other things to check: water in your fuel, a fault in your fuel or electrical systems, faulty or incorrectly gapped spark plugs, brakes that are binding, ATF level off, fuel filter clogged, emissions not operating correctly.
What to do with each:
1. Water in the fuel: run some dry gas or SeaFoam through your system, and see if performance improves.
2. Fault in the fuel or electrical systems: Pull the codes that you have and go from there. A Haynes Manual is probably going to be needed; either way, it's a good investment.
3. Faulty or incorrectly gapped spark plugs: Pull your spark plugs and check the condition. Anything other than a brown to grayish color indicates a plug problem. Correct the problem before replacing the plugs. Do the same for checking the gap; if it's too high or too low, replace and correctly gap the plugs.
4. Brakes that are binding: Check and replace all worn brake parts, especially if the pads show more wear on the inboard side of the caliper. Also check your drums and shoes for excessive wear, as well as if your e-brake cable is stretch and/or engaged.
5. ATF fluid level: Check and top off. Change if filter is suspected of being clogged or has not been changed in a long time (3+ years).
6. Emissions not operating correctly: I'd check the IAC system and the EGR system for faults; if a fault is found, repair and retest. If an 02 sensor is found to be faulty, replace it.
In the end, erase and clear all CEL codes, and pull the negative battery cable to reset your "learning curve" back to factory specs.