# told her everything

"told her the source of his strength" or "told her the truth". Samson mistakenly thought that he was the source of his strength. He did not realize that Yahweh had left him and without Yahweh, he had no strength. This was not Samson's only mistake. His foreign wife created most of his problems. 

# a Nazirite for God

"a Nazirite devoted to God" or "devoted to God as a Nazirite". See Judges 13:5.

# from my mother's womb

"my entire life" 

# If my head is shaved

"If someone shaves my head"

# shaved

to have had the hair cut close to the skin with a razor

# my strength will leave me

"I will not be strong any more"