Firstly i am so sorry about the loss of your dad. I also lost my dad and fully understand the pain and the grief that you must be feeling.
Holding on to the good memories and happy times that you shared with your dad is so, so important. I too turned to blaming God for taking my dad from me. I stopped attending church and stopped praying. I have realised though, that doesn't achieve anything. I am starting to appreciate the time that i got to share with my dad and realise how lucky i was to share such an amazing 16 years with him. You were his little girl and nobody can take that away from you.
I have suffered a lot of anxiety since my dad died, and depression as well, even turning to self harm to try and cope. But when i finally got help and sought counselling i started to make sense of my thoughts and found that talking about things actually really does help (as cliche as it may sound).
Honestly the best thing you can do, is to firstly, let yourself grieve in your own your way. You have have right to be angry, sad, frustrated, depressed, scared, its totally okay. If you need to cry, shout, scream whatever, you are entitled to do so. By accepting the fact you need help and by reaching out you are very much taking the right steps to progress. I found that once i opened up about how i was feeling i started to feel a little better. Talking to you doctor, or a therapist or counsellor can be really beneficial and they can offer you the right help and support that you need to start coming to terms with what has happened and help you find good coping techniques that work for you.
Best wishes to you and your family. Message me any time if you want to.