score:1
I must say that from the ECO's point of view your case still appears weak. The fact that your hosts in Britain are sponsoring you instead of your parents or spouse is weak point #1. In real world cases of sponsorship aside from family members mentioned above are rare. It is, therefore, a yellow flag.
Secondly, your weak point #2 is your profession. You want to be a full-time student and a part-time freelance writer at the same time, and in both cases you're stuck in the middle (for lack of adequate and clear cut proof of how you're supported as a FT student and lack of enough income as PT freelance writer to establish your solvency)
Being a part-time writer will not add strength to your case, especially since those funds are not deposited into your bank account. And the fact that your part-time earnings come from freelance writing does not prove your ties to the country. On the contrary, it gives the impression that you can continue to do so from the UK should you decide not to return to the Philippines.
Furthermore, the fact that you are the sole caretaker of your father works both ways. On one hand it may show that you intend to return to your country because you have a sick parent to take care of, but it may also mean that you might not be able to afford the trip due to medical costs associated with the caretaking of your parent. Showing docs to prove his medical needs as well as the money that your sisters deposit in your account from Britain and Dubai complicates the case prima facie and when ECO is doubtful of yoru case, his or her gut reaction is to strike it down.
Property which is not in your name but your sister's and the lease of the same that is in your name - again, this is not clear cut and a cause of confusion for the visa officer. Another yellow flag.
Including a letter from college that shows your degree exams are due soon is the only positive point that may show ties to your country. What is your official purpose of visiting Britain? Perhaps write a letter explaining your sister's situation and the help she needs during that period from a family member (you) and hope for the best.
Good luck.