Hugs Blackwolf....did you ever seek advice from a counselor at the high school nearest you or at your town's local public health center as was recommended in your earlier post? If not I hope you do.
Perhaps by saying "I don't know", you're being too vague with your Mom . Maybe the next time your Mom brings up the subject of your baptism, you could respectfully remind her that getting baptized it a personal decision and you understand why she keeps asking you about it, but you'd like the decision to be made in your own time rather than because you are being pressured into it. Tell her you'll let her know when you've made a decision and until then you'd appreciate it if she'd stop asking you about it.
Mom: The end is so close...when are you getting baptized Blackwolf??
You: Mom...I get why you keep bringing this up but I really need to do this in my own time. Every time you ask me that question it makes me feel that I'd only be doing it because you are forcing me to rather than because I'm ready. I promise I'll let you know when I've reached a decision, until then it would really help if you didn't ask me about it anymore?
If she disagrees or argues, just look her in the eye and respectfully listen and no matter how hard it may be not to comment on what she says, just listen. You've given her an answer, stick to it and make no further comment. Gently change the subject each time she brings it up.
Mom: Have you given baptism any more thought?
You: We talked about this before Mom....so anyway, do you need any help making dinner? I was thinking I'd make a salad.
Mom: I asked you a question.
You: Do we have any fresh lettuce?