Lets start with the short lever, that is to set your hydraulics in either draft or position mode. Draft mode (lever horizontal) should only be used for plowing and ground engagment implements. Position mode is used for mowing, grader blade, etc. where you want to set the implement at a particular height and hold it there.
Now as to the lift dropping when you push the clutch, probably you have a leaking hydraulic lift cylinder. Remove the side cover (keep your fingers out of there) and with the load up see if you do not see fluid coming from the top, if so that is your problem and you will need to R&R the cylinder. It can be done in a couple of hours if you drag your feet. If it is your problem replace it with the NAA piston, o-ring and neoprene backup washer. You may also need the cylinder, depends on how much scaring is there.
