Cis guy here, but I work with a few trans people as a support worker and have heard a lot about their experience that may apply to you.
Puberty is dodgy for everyone. The levels go up and down over a few years for all of the growth hormones, not just estrogen and testosterone. The level of change this causes varies person to person and the timeline is not the same for everyone.
The same applies to behaviours. Some people become very interested in presenting as a given gender fairly early on, others start that later, and some don't end up settling on a gender presentation at all or have multiple attempts to find something comfortable.
Voice training is a skill building exercise and it is really fun. Viewing it as a fun skill to learn will make it way less awful and may help to not generate dysphoria when it doesn't make you sound fem in the first ten minutes. I don't know how far along puberty you are and how much that has impacted your voice box but once you change the growth hormones the growth of your voice box will shift as well. It will take time for the physical shape to settle, so you need to learn how to use what you have to feel comfortable in your body. I would also recommend singing if you can as it gives you way more catchy ways of practicing a fem voice and is more fun than many of the more basic voice training exercises.
As for the fear of pushing yourself back into not doing things, yeah, it is hard. There will probably be days where it feels like that no matter what you do. There isn't a perfect way to do it. That said, you are doing something way harder than typical puberty, you are doing puberty+, the extension course in growing up. It is harder and it will suck sometimes, but you can do it.
What I find frustrating is we know what complaints will be made about this data in advance of doing the study, so why did they do this study? I get that they brought something new by articulating it well and bringing some data sources together in a slightly different way and so on, but what meaningful, tangible change is there to our knowledge with this study?
To be clear, no shade on the researchers, they did the best with the system they have. I mean the system as a whole. When we have study after study which shows that saturated fat is not the cause of heart disease and one side of the argument just refuses to change their mind to match the evidence it seems the scientific system is broken and will not move forward.
A conference on an issue like this would also not work because those same issues would turn up. A panel with 10 researchers would include many who are directly funded by industry. They can't leave that baggage at the door and think clearly. That simply isn't human nature. We can't expect people who have a vested interest in the outcome going a certain way to act with detachment and clarity. They are and always will be biased.