Deleted PS4 client, redownloaded, now can't log in?

Hello, I think I have just done a very stupid thing, but I deleted my PS4 client of FFXIV (the one I upgraded from PS3 > PS4 , bought the PSN version in hopes that I would be able to now preorder Heavenward through PSN, and now when I try to log into my account through the PSN client it tells me I have to create a new service account before playing. Is this a bad idea if I choose this option, is there no way for me to link my old account to this new one?

Just make it a 2nd service account. U should still be able to get into all ur old stuff, I know I can. Then u can go onto the log station and cancel the 2nd service account if u really have to.