Photoshop 2019 cc software download

Hello, 
I'm using the Imac old version. The I5 version. So the 22.2 version is going slow. 
I'm looking for the Photoshop 2019 cc versions. Because previouusly that works well for me. But I cant find that version in creative clod app. Can any one please guide me from where I can download that old version. That will be helpful for me. 

thank you,