Problems / Gear Box I Believe

[Flexus Lexus]

hi all!!!!

i have had a few troules with my is200 (Automatic) over the last 2 weeks, an it has now com to the point where it wont drive properly at all. i believe its due to my throw out bearing or flywheel,i put it in drive an take off it changes from 1st to 2nd then its as if it skips 3rd and drops it into 4th dropping the revs from 4000 to 2000 because of it changing from 2nd to 4th i believe........ also at idle it whines a little bit...... so i believe it could be the throw ou bearing because of whining noise or flywheel because it wont change to 3rd can anyone give another diagnosis please!!!!!!!