I'd have to agree that the narrative is the worst path to go down.
Last time I wrote just narrative was at the beginning of year 10, and my teacher made such an issue about it, shouting about how much he hated narrative, that I changed my style. I've been 1st, 2nd or 3rd ever since in all essay subjects (Ancient, Modern, English 2u, 3u and 4u, and Extension History)...
My point - break your essay up into themes - if you have an essay on Stalin post-rise to power, then you would go:
- Power struggle
- Collectivisation
- Industrialisation
- Totalitarianism (integrating into the others if possible)
- Purges
- 'Great Patriotic War'
And you need quotes from historians, and even Stalin himself if possible - it's not WHAT he did, but WHY nad WHAT EFFECT this had. It's pretty simple really.