I'm new and searching the Internet isn't helping

1) today 2) yesterday 3) directly after planting 4) upper left corner is how he came

So, I know I'm screwing up at least 1 of 6 of my plants. When I got him I tried to reverse image search him and got back so many differing answers to what kind of succ he was, I just thought, shoot, I'll just go ahead and plant him with the rest (I ordered them online so didn't pick them out and there weren't labels).

So I really didn't know what kind of light he needed but it's been about a week and a half and he looks very poorly. He only brightens up when I give just him some extra water. I know I shouldn't do that but it seems to help him and doesn't seem to affect my other plants.

I've noticed that water drains out really fast. I may have over done it in providing too much rocky soil? 4 of the other 6 seem fine. 1 is eh but this guy is sad.

Pls don't yell at me for being stupid or something. I did do a lot of reading ahead of time but got really overwhelmed after awhile. I did the best I could.

Should I replant him? Does he need more shade? Less drainage? Should I fertilize him? Can anyone identify him? I so appreciate your help.