Directly behing the transmission oil pan ain't a cross member and I suspect it is where your problem lies. Did you really get the car off of the ground using that support - WOW if you did. I am sure that is where your problem is. What the exact problem is I can't tell without looking underneath but I suspect something that was never designed to support the weight of the front half of the car is either bent or broke. Sounds like the rear tranny support. Your flex disc is in the vicinity and I would start looking real close at the front flex disc. If you are lucky it will be just a flex disc and rear tranny support replacement.