any gardeners here? can u tell me why my lettuce is wilted?

so i started growing lettuce from a stump a few weeks ago. i've been keeping it in a water bottle kind of like this, but longer, just with water. it was growing roots after two weeks and they look pretty good. it was going well until it started growing inconsistently. the stalk was growing taller and the leaves weren't growing very large. it didn't really look like how the lettuce i've seen online were growing. it kind of looks like this actually, just a bit shorter and with smaller leaves. sometimes i put it under a regular lightbulb for a few hours in the evening, but i heard that it has red light and red light is better for flowering and producing fruit than growing healthy leaves? so i usually keep it by an east facing window, but i didn't think it was getting enough sunlight so i put it on my west facing doorstep for a few hours in the afternoon yesterday. it was fine when i took it inside. and today i just put it there again for a couple hours. i went to go check on it, and the leaves were limp even though i made sure there was enough water in there. so does anyone know what's going on? i don't want to kill my plant. i was hoping to be able to harvest it but at this point i just want it to live.

Quote from ghostings

maybe the lettuce is not happy

it was fine a few hours ago

Quote from dummi

OH I think you didnt put enough water, since its getting more sunlight now it'll need more water as well to balance things out

i put some more water in. should i put it back outside or just keep it inside?