I'm no expert but I doubt that regular meditation (just sitting still and focusing on your breath or something like that) could cause those things. But of course meditation doesn't necessarily work well for everyone. I've been learning about mindfulness and meditation and it sounds like a good approach for me, but others may feel differently.
And of course, hi there and welcome, though I feel presumptuous saying welcome because I haven't been here long myself.But it seems to be pretty quiet here anyway. (I like coming here because it makes me own anxiety feel better even if for a moment, to think that I could try to offer a word of comfort to someone else... a bit selfish, yes). Sorry to hear about your mother, that must have been a painful experience and anxiety is understandable. I hope you can find someone you can turn to, even a doctor or therapist if you think that might be helpful to talk about the feelings associated with your mother's passing.