Engine sputtering, missing and flashing check engine light

I started it up yesterday and it was sputtering and jerking around and service engine soon light was blinking on and off fast. then after about a mile it acted like it got power to it and light went off and drove fine. today it drove fine until after about 12 miles then started jerking and sputtering again and light was flashing on and off. almost shut off at a red light, had to put it in neutral and give it some gas just to make sure I wasn't going to be stuck at a red light. I thought it might had been some trash in my gas tank or something, but I don't think that is the issue. any help would be appreciated. thank you