She isn't winning. This is her desperate attempt to avoid the likely outcome: a no deal Brexit.
Basically, both leavers and remainers hate her deal.
The remainers are trying to force her to abandon Brexit. The Brexiters are trying to force her to get out of the EU, in accordance with the referendum, without a deal if that's all that's on offer.
The remainers are playing their hand. As are the Brexiters. The remainers hoped to get an extension of two years. The EU has offered less than two months. That is a disaster for them.
They have also tried to prevent a no deal Brexit, but the EU would need to play along and they haven't really done so. Why? Because they have some elections coming up and they want the UK out before they happen. If parliament rejects May's deal again, the no deal scenario looks the most likely ending.
Damages everyone to some extent. But between them, the EU and May negotiated a deal that made little sense.
If they ignore the referendum result, there will be hell to pay.