I cannot use my trackpad in MacOS Mojave.

I installed MacOS Mojave and now my trackpad does not respond. It works fine before login (before I type my password) but not afterwards. There is another thread on this but none of the hocus-pocus solutions proposed there (NVRAM etc) work for me. I have tried them all. I contacted Mac support, and their only suggestion was to back up everything and go back to a previous version of the operating system, which would mean I cannot run software I need. I may then reinstall MacOS Mojave and hope that it works this time. This is not an adequate response, nor an adequate way to treat users who are trying to keep their hardware and multiple pieces of software running under conditions of a continually changing OS.