No, your sentence is not OK in my opinion. “I wouldn’t dare” would be used about something hypothetical/imagined. You could say “I hope I won’t break my phone, because I wouldn't dare tell my mom.” Or you could use it in a context like this: A: I broke my phone B: Are you going to tell your mom? A: No, I wouldn’t dare. Your sentence should be either “I broke my phone and I didn’t dare tell my mom” (if it was in the past) “I broke my phone and I don’t dare tell my mom” (if it’s in the present)

The difference is - have you broken your phone now, or what if you broke your phone in the future. NOW: I broke my phone, and I don't dare tell my mom. IN THE FUTURE: If I broke my phone, I wouldn't dare tell my mom.