I’m terrible at self-stretching too. I was never able to get a good stretch in my ankles, calves, or hamstrings until I started using these 2 devices to help me out: Blue Ankle rocker: https://www.amazon.com/Stretcher-Stretch-Achilles-Tendinitis-Pedal-Blue/dp/B086HBVX5B
Ideal Stretch: https://www.amazon.com/dp/B002UOSF06/ref=dp_iou_view_product_mobile?ie=UTF8&psc=1
They’re pricey but have definitely been worth it for me.