By 'restarting' the suggestion is that you give up on these and start from the beginning with new seeds. If these are indeed in preflower/flower that might be an option...given they're gonna be very very petite. I've thrown a lot of bad mojo at my plants too (being my first grow), but even so, they were 10-14" with some branches once they hit flowering. Still will never be huge, but that was reasonable to me.
It may be worth it just to see it to the logical end to gain as much experience as you can from it.