"forfeit my" is a correct and usable phrase in written English.
It can be used to talk about giving something up, usually as a consequence of a mistake or misdeed. For example, "I had to forfeit my privileges after coming in late for the third time."
If I win, I forfeit my victory and will still buy you a hot dog.
Yet while I wasn't bullied, I did forfeit my youth to a colorless heteronormative fairy tale.
I'm afraid he might be calling to say that this method just isn't working: I'm going to have to drop out, forfeit my fellowship checks.
He has agreed, but wants me to forfeit my security deposit as a penalty for allowing me to break my current lease prior to its expiration date.
I did not forfeit my right to engage in the political process and support political candidates by filing an Industrial Development Agency application.
But he has added a line warning that if I don't respond to the offer 90 days before the end of the current lease, I'll forfeit my security deposit.
The essence of Foster's coming out speech seems to be this: the right to live and love in the way that makes me happy, and not to lie or dissemble about it, is not conditional on forfeiting my privacy.
I'm turning over a new leaf, forfeiting my patent application on bulimia, and learning to write gooder.
Finding out he was a boy and forfeiting my chance to re-do my childhood through the little girl I'd dreamed up.
I will take the late shift, forfeiting my own sleep for yours, because I want you to feel human again, after too many sleepless nights.
Creeping out of my guesthouse in an idyllic Pyrenean town, I've forfeited my breakfast croissant in the hope I'll make it Cap D'Agde – the world's biggest nudist town – by lunch.
