HRT working or not?

I am 47 and on HRT patches. Started about 6 months ago and the first few months were great, no hot flushes, headaches went and just felt better. The last month or 2 I have found my headaches coming back. Low mood, feeling crap, poor sleep etc. my doctor will not do a blood test to check my levels as they go off of symptoms only ! But how do I know if the patches are working or how my body is absorbing etc. she said to increase HRT but can’t on the patch as only come in one strength??? My GP won’t test my testosterone even though I have zero libido. Any advice plz xxx