Your black point is wrong; you can tell because the film edges (which received no exposure) are not black. That is a scan process problem and because of it, we cannot tell you if your negative is good or not.

While scanning is offtopic for APUG, I should point out that there is no such thing as a "flat, no tweaks" scan. Film holds about twice as much dynamic range as paper or a JPEG therefore you have no choice but to select part of that dynamic range when creating a print (under the enlarger) or an image with a scanner. You must make interpretations. If you just take the whole dynamic range of the neg, you will get a flat grey result like you've posted; yours is unnecessarily flatter still because you haven't used more than 3/4 of the dynamic range of the jpeg.

And seconding the "use a commercial developer for now". It gets rid of so many unknowns.