Help!

I've been struggling with sleep maintenance insomnia for around 18 months, and I'm struggling to find any professionals willing to take an interest that can offer some sound advice, so I'm hoping someone on here might be able to offer some guidance that hasn't been previosuly suggested.

I have a history of general anxiety, worry and catastrophizing, and my sleeps issues started a few months after quite a stressful period. However, after 6 months of medication (Sertraline), following sleep hygiene best-practises, taking supplements (magnesium, L-Theanine and Apigenin), hypnotherapy and generally feeling quite good mentally without too much stress and worry, my sleep problems haven't improved at all. I can get to sleep OK, but I wake up every night between 1am - 3am, and struggle to get back to sleep.

My GP has suggested I go back on Sertraline. But, as I currently feel good about myself, I don't want to go back on antidepressants unless that is the only solution. So, I guess I'm looking to see if anybody has experienced something similar and has a view on whether they feel medication is the answer or whether there are other remedies. Also, for any suggested ideas, a corresponding time line would be good to know.

Thanks in advance. 🙏