No charging, no turning on

Hi guys, I'm very confused I have a dell Inspiron... And it undergone some circumstances in a short period of time , I'm a student and I use my pc on a daily basis, and by battery doesn't last long so most of the time am completely discharging it or use my pc with the charger. So what happened exactly is used it as my usual then went out with my pc in my bag ,in a very rainy day , when I arrived home I have checked it and it looked alright to me , not wet. So I've used it normally and slept with it on my knees, and at a certain moment it fell off and I found in the morning on the ground, so I checked it and it was turning on and charging at that time. So I thought everything was okay but , after a day of use , I left to charge and went out , when I came back found it not charging ( the led of the charger was on but the led on the pc no, which meant that the cable was okay but there was no power fed into my pc) I tried to turn it on and nothing.
Please can someone help me!