I would say take advantage of your 10 minute breaks! You’re supposed to take at least 2 a day if you’re working 8 hr days. Stretch, meditate, get up and go outside for a short walk to just get a little sunshine. Also if you wake up a bit earlier, it’ll give you more time in the morning~ I know it’s hard but it’s a change that will make you feel like your days have meaning and are longer. I feel as we get older, time flies by really fast, so every moment is worth making it feel longer! Good luck friend.
Just do the deep work when you can. I purposefully planned my sessions to be when I can't have other obligations interrupt me, even though afternoons were suggested.