I’m a massive proponent of the use of props in both asana classes and in your meditation practice. You can meet your body where it is on that day and really feel supported by your practice rather than it becoming just another thing that makes you feel that you aren’t enough (which obviously you are, just so you know!).
In the images below, Fil is beautifully demonstrating how the use of a couple of blocks and a blanket can totally change your posture. If you compare the image on the left with the right-hand one, you can see that just slipping something supportive under the knees makes a massive difference to what her back and hips are doing. Her spine is straighter and more upright and her knees are in a more comfortable position with her hips.
I spoke a few posts ago about the different ways you can sit for meditation and this is another way that postures can be adapted to suit you or someone in your class. Personally, I find that when I meditate early in the morning, those cushions mean I can let go of my body and let it all fade into the breath.
In order to fully 'let go' and really create the focus that's needed to move closer to the state of meditation, our bodies must be comfortable first. If your body doesn't go into full lotus (and I've said before why that posture may not be the most 'efficient' for meditation), or even sukhasana (cross-legged), or even get on the floor, provisions must be made. Meet your body where it is on that day, the rest will become easier.