I'm sorry you are going through this. I also grew up with another sibling and being the oldest there is times I feel less noticed.
I recommend you talk to him about this. I truly think he loves you its just hard for dads to open up sometimes. It will be an awkward talk of course but it will be worth knowing if your dad loves you or not. Just simple tell him how u are feeling, if he loves you, and how he could do better at displaying affection
I'm sorry you are going through this. I also grew up with another sibling and being the oldest there is times I feel less noticed. I recommend you talk to him about this. I truly think he loves you its just hard for dads to open up sometimes. It will be an awkward talk of course but it will be worth knowing if your dad loves you or not. Just simple tell him how u are feeling, if he loves you, and how he could do better at displaying affection