I have a 1999 honda crv automatic tran, before when I shift from park to gear there was some kind of hydraulic feel but now it does not(this is before driving off). And also when I take my foot off the gas it jerks, feels like am applying breaks on and off but am not. Do you have any idea what might be causing these problems? Any help will be appreciated, thank you.

I once toped up the transmission fluid and it worked for one week and then same, I drove it to the mech but half way there it wouldn't move faster than 40km per hour, the mech took down the tran cleaned the bottom pan and replaced it, it drives but still jerks when coasting and no resistance in the stick when the gear is changed from park to gears.

With problems of that nature, I would check for codes/pending codes. It may indicate, for instance, a problem with the Vehicle Speed Sensor (VSS) or Transmission Speed Sensor. Were you previously changing the transmission fluid and filter regularly?

Thanks txgreasemonkey, I don't think the speed sensor was checked, will bring it to the mechcanic's attaintion.
What happened first is the differential in the trans broke because I had different size tires. I got it replaced and it worked fine for one month then this. Before all of this the fluids were changed regularly. Thanks for your answer,highly appreciated.