i made the same mistake. only two fish though.
your tank has to cycle, it takes 36 days the old fashioned way, before a tank is truely safe. you can speed it up a few ways by, adding a used filter cartigde, adding start right, and a little bit of salt.
dont fret over adding fish to soon, my fish did surive for 3 weeks, but i did a bad
check your ph every day, twice a day for about a week, record the changes, and stuff like that. the fish should survive as long as you keep a close I on the tank and ph, etc. your ph is very low, it needs to be 7.0 it can stray to 6.8---7.3 but no more than that. i imagine your mollies will be getting ick very kwik with all of the stress going on in your tank. do not do any water changes for about 10 days, if you do u will go back to square one.
your fish should survive, you may lose a few though (mollies most likely)