Teach me when to quit a live session

[PorkchopDJG]

I have also found this question to be a tough one to figure out.
I have length of drive issues as well so no matter what happens I am going to play for a while. If I just go card dead or hit a really strong table and go down half my buy in I will either rebuy back up to my original buy in if I think the table is still good and I have been playing well or get a table change if I think my table image is shot or there are just too many good players at the table. If I continue either at the same table or a new table and lose half that again I will conclude it's not my night and usually just go home. Since I always buy in for 30BB's it will be a 30BB stop loss.

If I am winning I will usually stay until I get tired which is usually about a 10hr session.
I may also leave if I have played for at least 5 hours and either;
1)The table gets incredibly tough (may just do table change)
2)My table breaks and I have to move to another table and completely learn 10 new players.
3)The tables at the limit I play are all shorthanded.
4)I have won a lot but have given half back by lossing a few big pots and I am getting tilty.