Quite frankly, I think you need to pursue other career options.
In no way am I trying to be mean or tell you to give up on your dental dreams. However, after a long history of bad academic performance (6 F's), do you honestly think that you can start over and maintain a 4.0 and get excellent DAT scores? It sounds good in theory, but unless you transferred from a very challenging school to one that just hands out A's, then I don't see your 2.55 happening. And even still, someone with a 2.55 should not be competing with others who have done well throughout their entire academic career and achieved 3.5's-4.0's. I think if you had the capacity to do well and you truly did have the dental dream for so long, then you would've worked harder from the beginning, like most people who gain acceptances.
It might just be personally biased though. I cannot understand how many people have this dream of going to med/dental/vet school since they were a kid, but then take 5 or 6 years to complete college, don't finish their pre-reqs on time, do a post-bac or two, and apply 3-4 times, only to finally come to terms with the fact that they should consider other career options at the age of 30+. I was lucky enough to know what I wanted for myself, worked incredibly hard to build up a solid resume during undergrad and get accepted my first time applying, so I may just have a hard time comprehending that other people don't all do it like this. I just can't imaging having my life be in limbo for so many years waiting to begin my career and coming out with so much debt in my mid 30's. I took just one year off between undergrad and dental school (to work for 1 year doing research and get my application in order), and I couldn't imagine taking any more time off. I guess if that's what you really want for yourself though, delaying reality, then keep going after your dream.
I think it would be quite shrewd to start looking at other careers. You may even find something that you like better!