Have you ever tried re-negotiating already signed SAFE note?

Re-negotiating is all about leverage and after signing, you have none. SAFE's are pretty standard, so I presume you aren't happy with the Cap or discount. Here are a few things to consider, before you become a huge problem for the CEO:

- If you invested at the tail end of the good times and are upset that everything re-priced, that's just how things go sometimes.

- If you are a part of a round with other investors, you all have the same terms. Changing just your terms will create problems. Changing everyone's terms will create problems.

- Early investing is about swinging for the fences. No matter what the terms, as long as they are somewhat reasonable, will have great upside. If the company is a bust, your investment is worth nothing. If there is a small / non-existing exit, you have blah returns. A little more or a little less doesn't really matter.

Unless there is more to it, you're probably having buyers remorse. It sounds like you weren't really mentally prepared to invest in startups and that's a tough place to be.

Best of luck.