You said that you replaced the fuse and it ran for awhile. Then you replaced it again and it ran for awhile. This isn't a coincidence.

There is a fuel pressure test port on the upper fuel filter bowl. You probably need to check fuel pressure. If you go down to the 6.0L Diesel forum and read the tech folder, there is a procedure for testing the output voltage of the FICM. The FICM bumps the 12V battery power up to 48V for the injectors. Low FICM voltage is a common problem and will cause some of the issues you have described.