I’m losing myself

I have a one year old daughter and my 6 almost 7 week old daughter. Every since my newborn has arrived I feel like I’ve been so harsh on my one year old but I swear I don’t intentionally mean it. I just feel like she has been getting into way more stuff and acting out WAYYY more. And when I try to tell her to stop or no, I feel like I’m doing it way too aggressively or strong. (I don’t hit her, but a tap on her hand will do sometimes)... I love my babies with all my heart I swear I do but I don’t want her to think that mommy is being really mean. It’s just over wheeling when I have baby in my arms and I have to rush to her to grab whatever she’s not suppose to have or juggle with her too. Any advice?

When she’s napping I go through the house and make sure everything she’s not suppose to have or reach is in her way but it still seems she gets into something..