Tony, I know your probably a bit taken aback by this thread. But you are speaking to people with a lot of experience here and the advice given is not an exaggeration. Some of these people are expats who've lived in the Philippines for years, others that have been burnt before in the Philippines and some who have just travelled a lot.
You may be able to change your flights with Emirates for a small fee, and I would highly recommend that, because going ahead with this trip so poorly planned and with such a smaller budget, you could be putting yourself in a seriously dangerous situation.
As has been said before, you need to be self sufficient should the worst happen. Some people have taken quite a lot of money with them and easily spent it, but I reiterate you WILL need AT LEAST 100 pounds a week to survive AND a credit card with at least enough money to get you home AND a comprehensive travel insurance policy. If you don't have this, don't even consider going as you could end up in a seriously bad situation.
Again, remember that things don't always go smoothly, the family may not be what you expect, you may get ill, your flights may be delayed, your baggage may go amiss, you may not tolerate the heat, you may get robbed, an emergency may happen at home.... who knows. I don't want to be a spoilsport, but most of these things have happened to me at one time or another whilst at the otherside of the world.
As for help from the British Embassy, if you have travel insurance, or there is a political problem, they MAY help you, but you can't be sure. If you run out of money, or get yourself into some local trouble, what they can do is limited.
And AGAIN as I said before, presidential elections are almost upon the Philippines and this WILL result in rowdy and aggressive political rallies, this WILL result in gunfights and murder (did you see the news a few months ago with the mass slaughter over the political rallies?). This isn't a reason in it's self to avoid the Philippines, but it is something worth being cautious about and knowing who you trust and where you can safely go. White bloodshed would make a nice political statement!
