how to tell if i need a new head on my 92 toyota pickup 44re?

[Golden]

my truck over heated on way to work so put antifreeze and water in it and drove to work then home had no power going up hill and then water was coming out of front not sure but think the radeator and white smoke coming out of the exhaust. do u think i just need to replace the head gasket or do i have to replace the head. i don't have money so hoping its the cheapest to fix and how much do u think it will cost for what u think it may be?? please help im sick to my stomach also, how long do u think will it take to have it fixed i need it fixed asap to get to work no buses go that far to my work it's horrible