Overwatering.. Will she survive?

So I woke up this morning and my plant was looking terrible. It transformed over night and now the leaves are sagging and drooping down and the stems are weak. The top of the main stem cant even hold itself up anymore so i had to get something to help support it. I'm pretty sure I over watered it the other day... I began to see some nutrient burn after fertilizing so i decided to give it a minor flush to try and fix it. Do you think the flush gave it too much water which is causing the leaves to droop??
I tested the PH of the water run off too and it looks really low like a 4 or 5 even though the PH is 6.5 before watering. You think the PH might be the problem? The plants been growing for 1.5 months now and looked beautiful before this morning so I don't see what else could cause the problem. You think it will return to normal if i slow down the watering??
I'll try to get a camera and get some pics to help see.

lets see some pics... and dont water it at all for awhile. When growing in soil the plants basically tell you when they need to be watered. At least that's how I do it, heres what I mean...

When your lights have been on for a little while your leaves and branches should be "perky" if you catch my drift. They can even be firmly pointed upright. With experience you'll understand what im saying. After a couple days or so during your light cycle the leaves and branches will slowly start sagging and drooping a bit. The longer they go without water the more they will droop, the top can even start leaning over. If this is happening while lights are on, its time for water. Now, if it's gotten to that point to where the top is leaning over, it's probably overdue for a watering.
Then just give it a moderate amount of water... just enough to where you get maybe a little runoff out of the drain holes. An hour later, bang... perky leaves and branches again.