Starting problem-ready to pull my hair out

97 Rodeo V6 with 5speed manual bought used from freind. Knew there was a starter problem before I bought it but $600 plus a starter well it was a steal. Or so I thought. Ran fine across the county home after we popped the clutch until I got about two miles away from the house and then the motor started lugging on acceleration. I figured it was because it was because the battery was dead from sitting up so long. Charged the battery, replaced the starter, and still wont even click when I turn the key. The positive cable connection to the battery is slightly loose but it was not loose enough to register over 12 volts on the gage. Only things in the cockpit working when the key is turned on is the gages and lights on the dash. No radio, no heat/air, no interior or headlights/taillights. Any ideas?