Some carefully placed water buckets might be able to hold them just out of range of hitting you with potions long enough for you to get past them (lava works, too, but be careful of drops (like your stuff!)), and then follow general advice for hurrying up the process of them simply de-spawning.
I've been base-blocked by witches and skeleton trapsskeleton traps more than a few times early-game, and water buckets came in handy. I tend to settle into the first plains biome I can find, at least early on.
They're much easier to kill with a ranged weapon, but some water might keep 'em out of range. You could also run over, grab your stuff, then use an ender pearl to get out of range in a hurry (but that requires you to have an ender pearl). That way, at least if you die again trying to get your stuff, you die away from the witches.
If you have 3 iron ingots, your best bet is probably a bucket and some water (if getting you stuff before it despawns is super important, and you have no ranged weapons, ender pearls, etc).