Deadlift help!

Hi Everyone,

This is my first post here and I am on week two of FB Complete. I was wondering if you could help me with some advice on deadlifts? I am really struggling as I feel the weight in my shoulders or lower back, and not in my legs where I just feel a stretch. I try and push my shoulders back and keep my upper body straight when I bend, and it seems like I am doing this in the mirror, but I just don't feel it in my hamstrings/glutes. I know I need to lift a lot heavier here, but my upper body won't let me! Any advice greatly appreciated!

Just as a FYI I am relatively fit and strong but haven't ever done these before in weight lifting. This is just so frustrating for me!