1997 Dodge Caravan Lose RPM's and grinds when accelerating

We have a 1997 Dodge Caravan ES with almost 150,000miles on it, it's been struck by lightning and is on its third transmission been on that transmission for 10yrs. Just recently the van started losing RPM's whenever we idle, put it in reverse, turn the wheel, or have the AC on almost to the point of turning off but hasn't done that yet. When it does this while we're driving it it won't accelerate so you have to punch the gas a bit to get it going again but when you do something on the driver's side grinds and then stops and it drives like normal afterward. It recently started happening more frequently and we're afraid our van is about to die. We just changed the oil and all the fluids are topped off now but still does it. We did notice it is leaking engine oil a decent amount it seems by the puddle in our driveway and the amount on the engine itself. Any suggestions as to what we could do to fix it? We are at a loss.