Advice.... don't scare yourself. I don't know much about SS rules but there are people here who do know SS very well. It doesn't sound like you're in trouble.
I would think the worst that could happen is that the part time work paid well enough to affect your benefits then the difference will be deducted from your future checks until whatever the difference is paid. Try to relax and stay calm
Don't hire a lawyer until someone here with a good understanding of SSI and earned income replies to your post. Take care