Help me to fund my Kenya expedition

Hello, I'm Heather, and I am trying to cover the cost of a once-in-a-lifetime expedition to Kenya, which I am to undertake with the group Camps International in collaboration with my secondary school the summer before I go to university. The final price of the trip comes to just over £4,000, and despite work covering some of this cost, I am still a full time student with an ensured minimum wage of just £6.40 and undertaking my most intense exam year yet, so I don't believe I could cover this whole cost on my own.

These funds will allow me to travel farther than I ever have before, and undertake humanitarian and educational efforts. These would include things such as helping to plant trees, de-worm livestock, build elephant deterrent fences, and do low level construction and plastering work. I would also have the opportunity to trek the Marungu Hills, and meet the Maasai Tribe and Tumaini Women's Group.

This is, as I said, a once in a lifetime opportunity, and so any help that people would be willing to give to get me there would be greatly appreciated!