Ex melting my phone

Hi!
Sorry for my english here.
Me and my exwife are divorced for more then a year now. We have two kids which live 50/50 with us shifting weeks. I love my kids, I love when they are at my place. The problem is that each week my kids are with me my phone is melting from my exs calls. She calls in the morning, when I leave kids to schools: "are they ok, did you dress them properly". She calls me during the day, always with "urgent matter". If I can't take the call she calls all my phones several time and then sends couple of sms. She calls me after the school "are you already at home? are the kids ok?". She calls me after kids are asleep "have you already put them in bed?". 
She explains this that she does not "trust me" and "if a stone falls onto my head she needs to know". 
If we go somewhere with kids and she gets to know about it beforehand it is usually ends up with tirade "you should watch them properly, don't leave them out of your sight, if something happens I will kill you" this of cause follows with a bunch of phone calls. 
Now it's still "gemensamt vårdnad", and they live at my place half of the time. I wake them up in the morning, bring to schools, pick up in the evening. We make home tasks, we play. On weekends we find something interesting to do. (It was so even before we got divorced.) If she cannot pick up kids from school on her week, I do it and bring them to her. It's almost always me who drives kids to schools, even if it is her week: "because you have car". If she has exams (she still studies at university) I take kids to my place for a couple of weeks in row, so that she can study. During this 1.5 year separately there were not a single accident when the kids were with me.  
I got tired of all this phone calls each day, so I stopped answering at least 90% of them. Now she threatens to prohibit me to travel with my son on summer vacation to another country "because there is no cooperation and she does not trust me". 
Is there anything to stop this nightmare?