Site Address URL and forwarded/masked domains

I just set up a blog for my new URL https://www.lifeafterforever.com. I have another website called https://www.shakingthetree.ca where I have a hosting account.

I set up a folder for my new blog under https://www.shakingthetree.ca/lifeafterforever/blog, and in the GoDaddy control panel for the lifeafterforever domain, I had it forward/mask lifeafterforever.com to https://www.shakingthetree.ca/lifeafterforever/blog.

The masking is working for users who type lifeafterforever.com and browse around my site, but the problem I have is that when I want to share the posts via Twitter or Facebook, etc., the full address of the post (ie. shakingthetree.ca/lifeafterforever/blog/11/08/the-ring shows up. I can Tiny.cc the URL but when users scroll over the Tiny.cc’d link, it still shows the actual physical address.

I would like users to see lifeafterforever.com/11/08/the-ring.

I changed the Site Address in WordPress to https://lifeafterforever.com but I get a 404 message when typing https://lifeforever.com into my browser after I make that change.

Hoping there is first, a fix, and second, that it’s an easy one. I am not all that uncomfortable going into my database control panel at GoDaddy as I just had to so I could actually log into my site again after playing with the WordPress address.

Not too great with editing the .php files though so if that’s what I have to change, please let me know exactly where I would have to put the code you provide me in as much detail as possible.

Thanks for your time.