When you say the touchpad isn't working, do you mean it won't physically click/move, or it clicks but the device doesn't seem to register it at the software level? If the former, especially in light of the high fan usage, it is possible the battery has swollen - necessitating removal/replacement. According to Apple (https://support.apple.com/en-us/102172#:~:text=One%20of%20the%20functions%20of,might%20notice%20more%20fan%20activity.), the symptom you're seeing is due to the cpu being in danger of overheating.