My dad always let us down.

Im 16 years old. I have two older brothers and 1 sister. My dad left when i was 5 years old. We use to go up at the weekend. But he has a drinking problem aand i hate being round him when he is drunk. he said we shouldnt come up because we are getting too old. He always promises us things but never keeps them. We only hear from him every couple of weeks. Wen hes drunk he would txt us at early hours in the morning, saying he loves us and misses us. then we wouldnt hear from him for weeks after. i don't know if i want to have a relationship with a dad whos never there for us. the only time i see him is when he comes to me with his problems. but never asks how we are keep.

could i get a bit of advice on what to do please?