I enabled cross save before looking around the website and reading all the restrictions on trading. After realizing the mistake, I asked support if they can revert my account back. Thankfully, they did. Now I can trade with my friends and clan mates again.
My account was reverted back to its pre-cross save state so I did lose the bit of progress I made during my cross save state (I was forewarned by support prior to revert), which includes all the operation gargoyle's cry event rewards. I'm not worried about it though, I can earn that back in time... apart from the Krios Signa... that one hurts.
Overall, thanks to support, [DE]Liane and everyone who worked on my request, everything is back to normal.
See you out there, Tenno.
edit: I also got my forum account back.