Welcome back to the community. 
If you are having trouble launching WeMod or getting it to run correctly, then there is quite a high chance that a security program on your PC is interfering with it, even if it didn’t do so before. Troubleshooting for this can be found here: I can’t Install WeMod / "There was a error installing the application" - #2 by Ravenfyre. The title of this page is slightly different to your issue, but the steps are the same.
As for resetting your password - ensure that you are checking the correct email address. It’s possible that when you registered back in December 2017, you used a different email address to your current one.