Hamstring sprain

Hi everyone!

So today I woke up with a sprain in my left hamstring. I've been working out for more than a year and this is the first time I've experienced something like this. I'm just wondering if anyone has advice for what to do? I've been icing it every couple of hours and am going to do an upper body workout today. Should I stretch my hamstrings and go for a walk or is it best to rest it completely?

Any and all advice helpful, thank you so much guys!!! 💪