1995 Cadillac Deville Sedan

I purchased my Cadillac second hand in October it sat for a couple of months and drove smoothly. One month later I noticed a small transmission leak. The leak has since gotten much worse you can see where I am driving there is a line of fluid behind my car also when I have my foot on the gas she revs and idles really high when I remove my foot off the gas she lurches forward really fast for a moment. She does not overheat and has had an oil change in October. The transmission smells hot. When you hit the gas to take off it takes FOREVER to hit second gear she goes 10 mph for a good 2 blocks then switches into second and maxes out at 30 mph. Then it doesn't want to shift into 3rd till the RPM's are way up. During this time you can hear the engine revving loudly I take my foot off the gas as not to blow the engine. The engine runs like a dream it is the transmission that is the problem.