can I download software for my iphone 5s without itunes (because itunes download is slow)

What's disabled? Your Apple ID or your phone?

If your Apple ID is locked or disabled - Apple Support

If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

If your phone is disabled, you have no choice but to restore iOS using iTunes.

You can download apps from the app store on the phone. App purchases and updates are no longer available from within the latest version of iTunes for Mac and Windows.

No. iTunes is the only option.

It's not iTunes that's slow, it's your Internet connection. Nothing we can do about that.

inventortari04 wrote:

itunes is too slow

It doesn’t really matter what your internet speed is. The only solution to a disabled iOS device is to restore it in iTunes.