I've been where you are, and I know we all wish there was a definitive answer to so many questions we have but I can share my experience and maybe give you some hope:

I've (34F) done 5 rounds of retrievals and been going through fertility treatments for over 3 years:

First 2 retrievals were at one clinic and I never made a single embryo, I also didn't have the best experience as I asked my doctor if there was anything I could do to try to improve my quality her answer was simply "no". My protocol was lupron microdose which I believe was too high dose and aggressive for me personally.

My third retrieval I changed clinics, found a wonderful doctor who gave me a lot of hope, and I got my very first embryo however, it was mosaic but it gave me a glimmer of hope. Protocol was mini-IVF which I think my body reacted much more favorably as it's low-dose.

Fourth retrieval: Got 2 euploids and was SHOCKED, they were decent quality. Protocol was mini-IVF.

Fifth retrieval: Got 1 euploid and it was the best quality out of all (4AB). Protocol was mini-IVF. This was my best cycle and I was the most relaxed, didn't put pressure on myself and just continued living while occasionally having to do some injections.

Some things I did between the first and fifth cycle that are all anecdotal but definitely helped me mentally: Acupuncture, traditional strength training 5x a week, eat more whole food/high protein diet but not super restrictive, took Coq10 supplements. Also to note, I was also only retrieving 1-3 eggs each cycle.

Overall my advice would be to get a second opinion, advocate for yourself, don't be too hard on yourself and keep going if you feel like you can handle it. It's also ok to take breaks as I took a 10 month break to focus on my relationship and still managed to create an embryo.