I also sit under a lamp and thought that was about as well lit as I could get, but recently bought a cheap neck light and I have to say it makes quite the difference! This is mine but there are lots the same www.amazon.co.uk/dp/B0BRZ8MKKC
Might be worth a try if you’re really struggling with it.
As far as the lightbox thing goes, if you’ve got any kind of tablet you can get apps that just light up the screen white and use that. I’m more of an old school “always has the laptop out” person so I can hold my project in between me and the screen and get the light shining through from that instead. Basically just anything emitting light behind the fabric.