mudsticks
Obviously an Aubergine
Just google, eg lie with legs out straight, towel round foot and pull foot towards you
BUT go see a physio first to get properly assessed / diagnosed
Yes worth getting properly assessed.
It may be something else as well as the hamstrings.
If you do try the DIY ones be sure to follow all the instructions and work evenly both sides.
Keep your pelvis level.
And your shoulders back and down.. Use a long belt or strap.. (or towel)
And understand that you've got to engage the front of the leg properly to get a safe and effective stretch, on the back of the leg, otherwise you risk injuring your hamstrings.
So basically you engaging your front thigh muscles, and pushing them away from you, as you bring the foot towards you.. With a properly straightened leg, kneecap flattened.
You can do a similar thing with your foot lifted onto a low height.. Probably no higher than a chair seat.
If your hamstrings are tight you might not get the lifted leg to more than a 45' angle
from where it started, either lying down or standing.
This is pretty standard for guys with short hamstrings, but if you keep at it carefully, and persistently, you will see an improvement.
I would post a picture.. But I've got a yoga class to do.
So maybe sometime later.