If you have emergency unforeseen repairs that are going to take four months you can get evidence of this from your builders and claim on the host extenuating circumstances policy to cancel @Antonio4803
What happened to your property by the way that requires such extensive unexpected repairs ?
I'm assuming you have unlisted your property as your profile says "Guest". Probably best to contact Airbnb and provide proof of the emergency repairs that are required to the property making it impossible for guests to stay. They can then cancel the bookings for you so you don't get penalized for the cancellations.
I'm sorry to hear you need to do some repairs on your property, I hope it all goes well and swiftly!
Have you had a chance to contact customer support, as Helen and Joan suggested? If not, you can reach out to them via this page: www.airbnb.com/help/contact-us/