99 G20t morning problem only

[kmlrt1]

My 99 G20t auto with 84k miles is having a morning problem. It's a little rough when I pull out of the driveway on the first start of the day. Put it in drive and try to go and it has trouble increasing speed. (rpms don't increase when pressing gas peddle.) Then I reach end of street and the rpms "dive-domb?" and the car shakes hard but does not stall. I slowly move up the street and all is well the rest of the day. Only happens on the first morning start. I'm in Calif. so it's cool but not terribly cold. The only thing I did a couple of months ago diff is had a tune-up and the guy said regular or platinum plugs and I chose reg and noticed my manual said platinum. problem? Thanks for your help people.