Toyota Repair: 1990 Toyota 4-Runner, toyota 4 runner, cylinder walls

Question
The problem I am having is that I drove my 4-Runner to work, which is 30 miles one way, and when I got to work, the oil had leaked completely out.  Before going home, I put a gallon of oil in it and then when I got home, the oil had leaked completely out.  I checked it out in the morning by power washing it.  I believe that it is leaking between the block and the head because I see some blue sealant in that area.  Before this happened, I did not have much horsepower and then this.  What should I do?  Please help, because I want to keep this truck and I need to know if it will need a new engine or could be fixed without getting a new engine.

Answer
There must be a huge oil leak for it to leak out this fast, without me being able to look at this I really have no advice other than to try to find this leak. Unless the engine was run completely out of oil and there is some internal damage to the bearings, cylinder walls etc. or excessive noise the engine should be ok.