It sounds like a Doppler wouldn't work, you know you are pregnant you just won't let yourself connect.
I would be worried about how you will be after birth, you have a baby that needs to connect with its mummy you need to overcome this feeling if dread or you will never forgive yourself.
If you can I think you need to talk to midwife and see if they can help or refer you to a counsellor or something that can so you can try and start feeling differently before the baby comes.

All those feelings are valid but not healthy... I feel similar but I don't have the bump and only random feelings, I don't feel sick and i know I have rare conditions so am a little high risk, if it's a high risk I usually win the medical lottery so i find it hard to shake the feelings but I MAKE myself as I know I need to trust it will be ok to get through the next half of the pregnancy.