Hi Mazzy
You are describing exactly what my sleep pattern was like pre meno and pre HRT. I would literally wake every 2 hours, on the dot, needing to go to the loo. Back in those days I never had any problem going back to sleep though, but it was still very frustrating.
I complained about it to my doctor and she sent me for an ultrasound (the most uncomfortable thing I've ever experienced because you have to have a completely full bladder), but it showed nothing. I realise now it was just all part of the peri-meno fun. When my sleep totally went to hell back in 2010, and I started taking my first lot of HRT, the problem miraculously disappeared. So it was all obviously hormonal.
IMO, I agree that herbal remedies are a waste of money. I have never found any to be helpful. Just be a bit careful about melatonin. It isn't a miracle cure for insomnia. It's a hormone that prepares your body for sleep, but won't actually put you to sleep. You also need to be careful about how much you take. More is not better. The recommended dose is no more than 1mg. Taking more than this can produce next day grogginess, headaches, depression, nausea etc.
Considering that we only naturally produce just a small amount of melatonin (I think I've read that it's less than 50mcg, but I could be wrong) it's not surprising that a lot of the commercial melatonin products, that routinely contain more than 3mg, could cause problems.
There are certain foods that contain natural melatonin, like sour cherries and sour cherry juice concentrate, so that could be an alternative you could try.
If you want to try an over the counter med, I have found a med called doxylamine (it's an antihistamine) to be very good. It is sold under a variety of brand names and I have found it very effective at low doses. I also post on another forum, where a lot of people experience sleep problems as a side effect, and a lot of them use this med with a lot of success.
Something else you could try, which some people on this same site find helps, is Magnesium Glycinate (glycinate is better absorbed than other types of magnesium).
Ultimately though, if your problem is the same as mine was, maybe you next course of action is to consider natural HRT.
Whatever you do though, don't allow your doctor to prescribe any kind of benzo or Z-drug to help with your sleep. Trust me, this is a very slippery slope to embark on, and it will only lead to further, and much worse, problems in the future.