26 y/o daughter live in carer for 80 y/o father. Any advice?

My father won't let me claim carers allowance, as he is too proud so I'm trying to work full time whilst care for him. (Cook all of his meals, take him shopping or do the shopping, Clean the house, do his laundry, manage all bills, take him to doctors appointments etc) my relationship is on the brink of ending, I suffer with severe depression and endometriosis which may relate to fertility problems but I can't even consider trying for a baby whilst I'm living at home with my dad. I don't know what to do, I love my dad dearly, he has supported me so much but my life for the past few years has been horrendous, he has 4 other children but they all have their own families and don't help, I'm the youngest. I feel I'm being selfish but I'm struggling to cope on my own!