you've got a short somewhere... DO NOT replace that fuse again, without finding it and dealing with it
if you do not fix the short, you risk an electrical fire in your truck, which could result in major (complete) vehicle damage, personal injury and/or death
the good news, this is why fuses are there... if something like this happens, they blow and cut the power before fire takes place...
to fix it, i would find which fuse it is, there will be a number, find out what it powers (radio, turn signals, ect) then start tracing wires, look for worn insulation, or a wire trapped under a bolt... did you recently buy this truck? if not, did you recently do ANY work under the dash, or have you wired anything in, accessory wise, that was on that circuit?