i am so sorry to hear about your loss. you are not overreacting at all. you deserve the time and space to be able to grieve the passing of your dad. i think funerals are sacred events but some people just dont understand or respect that. ive never understood why.
i lost my mum a few years ago.. and i dont talk to my sister anymore after years of trying. i felt like it was affecting the way i wanted to remember mum so i just did what i felt was right for me.
it sounds like you did the best you could to make sure your dad felt safe and comfortable. youre a wonderful person and daughter for doing that.
i cant tell you what to do but i think you should follow your gut. i find it comforting to think of all the good memories i have with my mum. sometimes i cook her favourite food. i put a picture of her on the fridge so shes watching me cooking (i learnt everything i know from her). on xmas, i lit a candle in her memory and cried my heart out. she lived fireworks. idk what will happen with nye this year but if there are fireworks, ill be thinking of her. yes, there will always be distractions and people who want to deter me from my memories and time with mum, but, they dont have control over my thoughts. and they dont have control over your thoughts either. your time and your memories with your dad are precious and you are allowed to grieve in the way that feels right for you. sending you lots of courage. you keep being you and be kind to yourself.