I have had lots of chemicals so I know how you feel, it's so disappointing and frustrating. However they always gave me a lot of hope.
I am now almost 42 and pregnant with no help, after many IVFs and IUIs to have the last baby (ultimately successful on an IUI).
So I guess what I'm saying is, I now seem more fertile than I was at 36. Maybe all the hormones kick started something but who knows.
So I think it's a good sign you have had two pregnancies relatively close together and I think that might mean you could get one that sticks. I don't necessarily think that IVF or stims won't help you. Having more than one egg in contention is going to help your odds. Can you find a protocol (a low stim one) that increases the number of follies? Even having 2 is better than one i think. Probably IUIs or TI would be fine since you can get pregnant naturally. Good luck I am happy to share any of my protocols that worked.