Planning your Wedding in the time of post - Covid 19 can seem daunting. But its not always a bad idea of having an intimate wedding ceremony with only the people you love the most as of the new safety regulations.
Given that you've decided to postpone the wedding, the first set of people to inform would be the vendors that you've hired/booked
Pandemic or not, bugging your vendors about whether you can get a full/partial refund of the non-refundable advance payment you paid to book them is bad manners.
Hopefully, Sri Lanka will be able to get a handle on this situation within the next few months. Therefore, unless your wedding is due within the next few months, there is no need to be too stressed out about this.