1997 ford f150 xlt braking problems rear drums
 

The brakes seems to feel like they are bleed. When towing a trailer its seems like they are worthless. Already took the truck to dealership and independent shop. Some oneone told be theres some kind of brake module under the hood. The pedal does fall to the floor it just seems like theres a delay. But when it towing a trailer if very dangerous to drive.

You may have more than one problem.
The first thing to consider is to replace the brake master cylinder. The reason for this is; all the while the brakes worked ok the brake pedal only went down so far and sediment accumulated in the bore. Then when the pedal went down to the floor the sealing cups in the master cylinder went through that trash and most likely got scratched/ scored. If the pedal doesn't sink down when the brakes are applied now it will in a short while because those cups won't hold the pressure.
I would suggest that you start with replacing the master cylinder and see what you get. There is a special procedure to follow when doing this and if you are not sure what to do either check on u tube or have someone that knows what to do replace it for you. Brakes don't allow for any guesswork !