Trucks been running and starting fine for a while but last night when i tried to start it the starter wouldnt stop cranking, i turned off the ignition and it kept cranking, it only stopped cranking after i took my foot off of the clutch. Now the fuse for the starter is blown and any new fuse we put in blows as soon as we try to engage the starter. The starter is decently old, cant really say for sure as it came off of the previous motor. For reference the truck is a 2000 2.2l gmc sonoma that i wish was an s10. The only warning i got was earlier that day when id tried to start it i heard the starter grind, but it was for a very small amount of time and i thought i had just held it on too long. Any help with this would be greatly appreciated, if i can figure this out and not have to pay a shop to fix it then thats more money earned towards getting the turbo installed.
Edit: Not entirely sure if it is needed but the truck does have a leak on or around the rear main seal, oil is around that area but most of it gets blown back not forwards.

 

First I would check the starter relay and then the starter itself as the solenoid is probably bad. More than likely you will have to replace the starter.