comfort zone

I think the hardest part of sharing your space with any person is one's measure of comfort. We start off in relationships tip-toeing around, being the perfect version of ourselves but after a while you have to let your hair down. That's when heads start to roll.
I just moved in with my boyfriend of a year less than 30 days ago. It's been mostly a positive experience but there have been moments where I've felt overwhelmed and a multitude of other emotions that bring me to tears. Am I unhappy? No. Happiness doesn't just wash away when you hit an emotional wall. I say wall because sometimes I feel as if this person is unreachable. However, this is a difficult learning experience to say the least.
I find myself to be more sensitive and more likely to conceal some opinions I have to avoid an unnecessary disagreement. A lot of people might agree that holding back is the worst possible thing I could do, but let me explain. I have many quirks that an outsider might not comprehend and I am well aware of this. I would not want to be picked on every single time I did something different or behaved in a certain way. A critical analysis of any of my off-color behaviors is only necessary when I am harming someone else. If it's not harming you, why complain? We can't have all our needs met in all circumstances. It's not humanly possible. Well, at least not when you share a bed.
I think I just feel like I am having a hard time even considering another person when I make a decision. I'm used to making decisions for myself, not for me plus-one. And at the same time, I feel like this person is also being selfish in ways that hurt me. Not all the time. It's hard to measure; half the time I think I may be overreacting and others I feel as if I'm warranted to be angry. I don't know where my comfort zone is supposed to sit. My stress level feels as if it's through the roof, but isn't that normal?