Why is my blender making a weird grinding noise and how can I fix it

I've had this blender for about a year now and it was working perfectly until last week. I use it mostly for smoothies every morning, but suddenly it started making this awful grinding noise whenever I turn it on. It's like the blades are struggling or something! I checked if there was any food stuck in there, but it looks clean. First, I tried unplugging it and plugging it back in, but that didn't help. Then I disassembled the blade part and washed everything thoroughly, thinking maybe some residue was causing it. Nope, still grinding. I even tried blending just water to see if it was the ingredients, but the noise persists! I'm worried it might be a motor issue or something more serious. Has anyone else experienced this with their blenders? I don't want to buy a new one if it's fixable. Oh, and it's one of those high-speed models from Amazon. Any tips would be great!