Welcome to the Bunnings Workshop community @Dannik. It's great to have you join us and many thanks for your question.
I'd suggest you first price a new cabinet door. I would be of the opinion that the cost of the products to temporarily fix this door might come close or exceed the cost of a brand new door.
Once water damage gets this bad that it has expanded the internal chipboard there is not much that can be done to save the door. You could bind the remaining particle board with Aquadhere PVA glue and then clamp it together. You would need to use several clamps with two pieces of timber on either side of the door and compress the particles back together. You will find it hard to compress the board now that it has swelled and it is unlikely to return to the original profile.
If you are successful are fixing the top then I would head into your local Bunnings store and pick up a selection of the white and off-white colour cards. You can use those at home to find the closest colour and then have the store mix it up for you in enamel paint.
Please let me know if you need further information on the method described or you had any questions.