When you say "playing 5/10..." you do mean $0.05/$0.10 blinds in no limit, correct?

A time limit technically isnt really a bad thing, it just depends on how you implement it. Ideally you would play for as long as you were alert and the tables were good, but in the real world there are time constraints and we cant really do much to change that. When I put in my sessions I try to have them last 2-3 hours or so but I dont necessarily hold myself to them if the tables are good.

Never set a winning limit, this is going to really limit your progress as a player and the amount of money you make. Play until you dont think you are making good decisions anymore, not because you reached some arbitrary number.

A loss limit is better than a winning limit but not really for the same reasons. I dont have a particular number that I leave after, but I leave when I know however much Ive lost is mentally affecting me and my play. I think setting a number on this may make you _more_ mentally susceptible to losses as when you reach that number you feel like you have to be affected by it.

Basically what Im saying is this, dont set limits on your game regardless of whether or not they are for good or bad reasons. Play when you have the time and stop if something else comes up that you would rather do, you are tired and not playing your best or the losses are mentally affecting you.

I really doubt that the fact that all of your sessions start out up and then slowly your profits drain away is solely because of variance. I think the fact that it is so consistent shows there are a lot of leaks in your game that need to be plugged. Start posting some hands where you are bleeding chips from your stack. Read the stickies to get a better grasp on the theory behind the game. Sign up for session reviews to have somebody's input on _all_ of the hands from your session. There are a lot of things you can do to work on this and you seem to have the attitude that will make that easier. The sooner you start these things, the sooner you will become a successful player.

EDIT: That was a lot longer than I thought it was.