[ukrkoz]

could be anything.
read codes 1st.
measure fuel pressure next.

this issue is discussed all over the web. some say, dropping tank is OK. many say, it is much easier to scoot truck bed back, to clear the fuel pump and sending unit.
some say, 5 adults can take bed off completely.
some say, it is cleaning a ground wire on sending unit harness that does it.

pick your poison.

I'd say, should you have that truck bed moved, do as much replacements as you can, while you there.