Another tranny question

I just had my tranny rebuilt.1725$ and nine months later it has messed up again.It is a 4r70w tranny.My problem is that it wont shift out of 1st gear at anything under 3500 rpm after that it shifts fine unless im cruising along and i tromp it it shifts to neutral until I let off of it and only get on it hard enough to downshift to 3rd.Fluid smells fine and is at correct level could this be a tc issue?Wanna switch it over to a t45 5 speed but need a complete list of parts for the conversion.Just cant afford to have the auto rebuilt every 9 months.And Ithink I drive too hard for the auto anyway.Any ideas or recomendations would be appreciated.

Converting to a stick isn't cheap.

I have seen the product for 450 to move the trans stick back to the correct location. Getting a trans on there may cost you though. I want to do it also. BAD!!