Problems again. Pics*

I transplanted it like 2 weeks ago, and it was doing so good up until now. The leaves are drooping out of nowhere.

I waited 6 days to water it which was saturday, and it was looking really healthy up until yesterday I saw these spots (in pictures). Then the nest day I come home to it all droopy and sad.

When I watered it I gave it a half gallon. Should I have given it more? It's about 2 foot tall now. Any help would be greatly appreciated, and repped accordingly.
The last picture is from yesterday with the spots.

It may be rootbound or the roots hit upon a patch in the new medium that it doesnt like. This may sound wierd, but id almost recommend getting a fan to blow on the plant for a few days. This will cause the plant to transpire more water from its leaves and in turn, take more up from its roots. This is an old trick my grandmother would do to jump start large plants that became 'stubborn" after working with them.

She didnt grow cannabis, but if she did, it would have been the best shit this world would ever see.

also check ph cus it looks like yellowing going on at the bottom and workin its way up

I'll put the fan on it for a couple days to see if I can revive it. And I really need to get some sort of Ph meter. I read a comment on here the other day "If you're not going to do it right then don't do it at all". I think i'm going to take that to heart and start over if it dies.

It looks pretty good. I dont think it will die. Life likes to live, especially plants.
You may want to bend some of the larger branches down to get light inside the plant. Flouros dont penetrate leaf material well and if a leaf isnt getting light, the plant will let it die rather than waste energy keeping it alive. Since the plant is as mature as it is, bend slowly and revisit over time to bend the branch down lower. You arent going to want to bend all the branches as far down as you want them to be all in one shot. The nodes may break or split.

Well it seems as though it was under watered. I gave it a half gallon cause I was desperate to fix it, and 2 hours later I could see all the leaves standing out. Who woulda thought it would drink a half gallon in 3 days.