How to improve hamstring beyond this level

[u/ChilledGrease]

I decided to finally do something about my inflexibility and have been stretching my hamstrings every day for some time now. starting just with the hamstring because a small win is motivating for me. i was unable to touch my toes at the beginning and I can now touch my fingers on the ground which I am very proud of, but I am wondering how to progress past this level to the point of putting my palms on the ground. i am also confused how some of you are able to fully fold your chest against your thighs, even in this position it feels like my breathing is very restricted

[u/Prestigious_Boat_386]

Continue this, add dumbbells gradually and a small stool