сцепить зубы

[Gontcharova]

Как следует перевести на англ "я сцепил зубы и терпел"...

[bystander]

i clench my teeth and endure (put up with it; swallow it; go on ... etc. depending on the context)
strictly imho

[watchkeeper]

also could be:
to bite the bullet
to stick it out

[d.]

bite the bullet

[Халеев]

I just hung on by the skin of my teeth.