How do you know when/if you’re ready for a second child?

My LO is 14 months and I am completely in love with her. She is my world. Annnnd now I’m feeling the baby itch- missing my belly, missing baby snuggles, jealous of people who are pregnant, and hog babies when visiting friends. I want to start trying in June so my daughter will be more than 2.5 when number is born. But I’m also really terrified 😢. It took 3 years to get number 1 and I’m so afraid of that emotional roller coaster again (hope, excitement, doubt, disappointment). Then I’m also nervous about the newborn phase. Our daughter was a really tough newborn. I didn’t feel “normal” again until she was 3 months. She would only sleep for 45 minutes at a time and would cry non stop from 9pm-2am. I still can feel the hopelessness I felt in those days and I’m scared the second baby will be the same. I could barely take care of myself during that time- how could I take care of a 2.5 with a newborn? I just don’t know how to let go of this fear while I’m also so excited for another. I also can’t imagine not giving my all to my daughter. Any advice or words of wisdom?