Missing in-game progress

I used to play Apex Legends years ago on PS4 and then on PS5, and I have a lot of progress, including Heirlooms and a lot of skins. I spent a lot of money on this, and then I left it for a couple of years. When I came back, I couldn't find any of my progress in the game. I have access to all of my accounts, but whenever I try to find my progress, for some reason I can't find anything.

I tried contacting support, but honestly they don't even understand what I'm saying. Their English is very bad, and overall it has been a very, very bad experience. No one can help me with that. Honestly, this is a plea because I want to get back to playing Apex, but I'm not going to do that if I can't get all of my progress back. 

I think the issue might be that I connected my EA account to a different PSN account than the one I used to play on, so the progress is not there. Now, when I try to unlink, it says that an EA account can only be connected to one PSN account in its lifetime, and it used to not be this way because I used to be able to change EA accounts as I wished. Now I can't do that, and I didn't know.

I'm in a place where I'm literally between a hard place and a rock where I can't move. I can't unlink, and I can't link my EA account to my PSN account. How can I do that? How can I restore my progress? I don't want to lose all of that money that I spent. Please help because EA support are going to be the death of me.