You Mom is thinking of leaving your dad? Ok, this is not just about you, can you see that part? She has something invested in a belief that you would be a JW against all the others, and against your fathers influence ( in her mind) Her over the top pressure is stemming from her self pressures, not you or what you do. She should respect your wanting to stay home. Especially since your father is not a JW. If you want to be a JW, if it was right, then you would go. Her actions are wrong, but not unexpected. Her emotions are very high right now. Hopefully you can rise above it, see it for more of what it is. Try to let go of some of that stress or guilt and see the whole picture. It's just not about you, it's all about her.
That said, continue to treat her with love and kindness and respect. (respect does not mean to change your beliefs because she told you to). She does love you, she is just very very pressured and conflicted, emotional... she is indoctrinated.