@molly74699 what you want to do right now is to stop trying to run it on. this potentially can make things worse. After all, you do have a water damaged device and may just shorten out things further.
Disconnect your power adapter, disconnect your battery and remove the motherboard. Use this [document|39235]to remove the motherboard (System board) as well as other boards as applicable. You will have to remove all the EMI shields as well as the fan, heat sink etc.. If you do not remove the shields, you are not cleaning the board.
Take a close look at all components and connectors. Truly assess the damage. Look for major corrosion, evaluate the pins in the connectors etc,. Take a look at all connectors as well as cable ends. . Once you got any gross contamination cleaned, use 90%+ isopropyl alcohol and clean your all of your boards some more. For a proper cleaning, use [guide|5825|this guide.] It was written for an Apple iPhone 3G but all the steps are still pertinent to your laptop as well. I can not stress the importance of a good cleaning enough, so do it over and over while replacing the alcohol after each cleaning.
The importance here is the cleaning. It would of course be best to get it ultrasonically cleaned. Do not forget to replace the battery. This is a must and not an option. It will fail if you do not take care of it now.
After that, reapply the thermal paste, reassemble your laptop, and re-evaluate. For as long as you have not cleaned your board and replaced the battery, everything is just a guess. Keep in mind that water damage is the hardest to troubleshoot and to repair. It does not matter if is was exposed for 2 seconds or 2 hours, what matters is where the water (particulates) did the damage.