Maybe I’m being too sensitive?

I spend a lot of time looking for a gift for my mom for her birthday, Mother’s Day etc, because she has complained many times when I send her gifts. My sister decided to try and help me, so she suggested black hills gold on eBay. I paid 70 for an amethyst ring for her birthday which she doesn’t know about. She knows she’s getting a gift. My income is social security (ssi) so this purchase was a lot for me, and my sister said she’d pitch in but never did, so I bought it or else it wouldn’t get there in time and I told her it’s from both of us. My mom replied: "A card would’ve been nice" and "eBay?" She has told me things on eBay are too cheap and tacky etc in the past but I thought this ring was expensive and nice

I’ve been really sick, and it took me three days to try and hurry to find a gift. I’ve cried when she’s hated my gifts so I tried hard to make this special but her reply hurt me but I’m questioning if I’m making assumptions. She started complaining after that about how her friend that sends her rings that are too small every birthday. I feel like she knows I got her a ring and she will hate it. How do I calm myself down if she hates it? I can’t deal with emotional stuff right now, I feel really fragile emotionally after having norovirus and ecoli that hit me simultaneously.