I’m sorry to hear of the frustrations that you are experiencing. I too know these frustrations. There is continual learning and experimenting in herbal medicine making, especially when making it by hand/small scale, without large machinery.
Getting all of your liquid (menstruum/tincture) out of the maceration (especially when the plant is ground up) can be so challenging and frustrating. What I use is a tincture press with my maceration inside a muslin bag. This is one of the best/easiest ways to get as much liquid back out of your plant matter (marc) once the maceration is complete.
Over the years I have come up with some creative things to do that does a similar job (before I had a press), such as a wide pasta bowl with another regular bowl upside down inside of it and the muslin bag containing the maceration on top. Then using a plate to push down on the muslin bag. The tincture/glycerite pours down over the regular bowl and is captured by the pasta bowl!
In terms of covering the plant, I’d say doing that double extraction to increase strength, that I had mentioned before might be your best option.
Wishing you the best of luck in the learning phase!