Need some advice

Ok so I have resolved the issue and I figured I would post the final fix. Yesterday I started the car put it in neutral and gave it some gas the engine started to die. So I cracked the gas cap and tried again and everything felt good again. I then tugged on the vent line and I could feel it give some resistance and then a pop feeling. What I believe happened is either I got the vent into the filler neck hole of the tank or it got under the gasket either way it is fixed now and working great. Thank you for all the help and I am sorry if my diagnostics were confusing. The problem confused me as well.