2005 Jeep Wrangler car won't turn over.

got in the car, turned the key, won't start or even crank over. the gauges would flicker but no dash indicator lights would light up. eventually, after trying a few times, they would light up but still no cranking. got a jump, it started, ran it for a bit, then drove it with the lights on (had to, no gas and it was dark out). the car died eventually when i'd push in the clutch to slow down. had to get another jump, filled with gas, got home and just let it run for 30 min with the lights mostly off. the battery indicator gauge was normal while it was idling with no lights. when i turned the lights on, it dipped a marginal amount. when i turned the fog lights on, it dipped about a quarter of the way to zero, then recovered a minor bit.

basically, is my battery just shot, or is it something in the charging system. i'd had no problems with anything electrical before.