Wrote a letter

So i wrote a letter for my boyfriend to read with all of my concerns because i have a hard time articulating my feelings. I’m really scared of how he’ll react to it bc some of it is a little harsh.

Ex: “If this is how our relationship with continue, you will lose me.”

I am very shy and passive, but i feel like i need to be more assertive and dominant in what i want. I really wrote it just to vent but i am really considering having him read it. I love him a lot. What should i do?