All the feedback i've seen about gasless MIG is 'don't use it'.
The MIG Welding Forum is a good resource if you are not already on there.
I have a lot of sympathy for your problem - the advice people always give is "keep practicing", which is no good for diagnosing what you are doing wrong!
Personally I looked at getting formal training - it's very expensive round here (Essex), i'd be looking at £500 odd for a 12 week 1 night a week evening course. But it might be the only way to really improve.
In the meanwhile, I am welding what I can that i'm happy with (which has been small parts, not on the chassis where I can get a weld i'd happy with and redo easily if i'm not) - and anything i'm not is going off to fabricators to weld, once i've prepped as much as possible.