I'm not sure why the buds died, but I will share with you what I learnt about orchid care a few years ago. This goes mostly for the Phalaenopsis genus, which is most common for sale. Growing medium: Chunks of pine bark, some orchids grow in a mix of bark and sphagnum moss, but the ones I had grew in pine bark only.
Watering: I used to hold the pot under running water for a while, then letting it run off. Sometimes i soaked the whole thing in water in the cache pot, and left it standing for a few minutes before I poured the water out. I did this maybe once a week, less in winter.
Light: Good light, but no baking summer sun. In the summer they can stand outside in the shadow or in dappled light, if the temperatures are not too low.
Feeding: Orchid formula, or regular plant food 1/4 strength, once a week or two weeks, nothing in winter. (But I live in north Norway, and it's really dark in the middle of the winter!)
I have noticed that if you touch the flowers, they may wilt and fall off sooner, someone told me that the plant maybe "thinks" that it has been pollinated. I don't know if that is the case, but I avoid fiddling with the flowers.
This was my piece of advise, others may chime in with more useful stuff. I wish you good luck!

Hi Sian87 :)

Bud blast is a common reason for sudden loss of flowers. Here is a link to inform you, and possibly diagnose the issue. Not sure if that is what happened, but I can't imagine it being anything else since the plant itself is healthy.

Here is a link that might be useful: AOS bud blast

yup, bud blast it sounds like.

Hi
That is a very common problem ,particularly with phals catts. Follow those guidelines on the AOS page . There are sooo many reasons for the reaction . . I just had that happen to some
floofy catts. and the never fail Vanda got snipped off by a squirrel lol Several phals aborted part but not all the buds!!
Take heart it will flower again!!! gary

While the outer, decorative pot is fine for displaying your orchid while in bloom, I would remove it and use only the clear, inner pot by itself during the growing season. I'm assuming it's clear, that's how most Phals are basically grown. That's because their roots also photosynthesize, just like their leaves do.

I would also trim away those dead flower spikes, and move your Phal to a much brighter location. No direct sunlight, but bright indirect sunlight would be best. I move mine outdoors once the nighttime temperature is no lower than 50ðF, where it's shaded almost all day long, except for some brief morning and evening sunlight.