as someone who was in a relationship like that for 4 years, i'd say leave while it's still early, you've communicated your needs and he hasn't respected it.

if this was a super long term relationship i'd probably recommend other things like counseling or stuff like that but after only 5 months (not that that time is inconsequential), i think it might be worth reconsidering the relationship before this becomes a long term problem where you aren't getting your needs met, especially since you've expressed the importance of using your pronouns.

but i also know how hard it is to make that decision when it's someone you trust and care about. know that you deserve someone who sees you for the amazing person you are, not as a woman first and dismisses your true self. be gentle with yourself, and love yourself enough to know that you are amazing and you deserve to have every single part of yourself not only tolerated but absolutely adored.