From limit 6max, its been my experience that you have to mentally accept that your win rate is going to be made up of huge wins and less huge losses. One of my problems when i switched was making the losses worse through tilt. I've more or less dealt with it, and just being able to look at the game objectively makes it obvious that shorthanded poker is a goldmine for a good player who can open up his game in a controlled way. 400 hands is nothing. But its a problem if you get mad about losing. Its going to happen. My win rate at party/crypto 6max is very good, but i still win only 60% of my sessions according to PT.
Speaking of which, PT and PAHUD are huge for shorthanded poker. Playing marginal hands and playing agaisnt people holding marginal hands is very read dependent, and thats exactly what you're doing most of the time at 6max. I'd gladly pay half my bankroll for those two programs if i had to.