waking up early is a common issue. It's due to cortisol spike around 2-3am. This is normal, but if u have a higher cortisol to begin with, the spike will wake you up and you will have trouble falling asleep.
ashwagandha does work, it's one of the few herbs that has a double blind placebo controlled trial showing it works on this particular issue
"The treatment group that was given the high-concentration full-spectrum Ashwagandha root extract exhibited a significant reduction (P<0.0001) in scores on all the stress-assessment scales on Day 60, relative to the placebo group. The serum cortisol levels were substantially reduced (P=0.0006) in the Ashwagandha group, relative to the placebo group. The adverse effects were mild in nature and were comparable in both the groups. No serious adverse events were reported."
/www.ncbi.nlm.nih.gov/pmc/articles/PMC3573577/just make sure to stop it after your sleep returns to normal, dont take it for months at end, it can get your thyroid into over drive (temporarily).