"You've reached the giveaway limit"

it takes support some time to get back to you

Not sure what you're asking. It's pretty much explained in the text you quoted already. Just open a ticket and request more slots.

for every 3 GAs that are marked as received you'll increase the limit of GAs you can create by 1, so keep giving and you keep getting more slots :)

What's the question?

You have to earn more slots, At first you can only post one at a time I believe. The more giveaways you do the more slots you'll get.

I think you start off with three giveaway 'slots'. You permanently lose a slot every time you delete a giveaway, to stop people spamming the place with troll giveaways. You get slots back when giveaways are marked as received plus you can make one additional giveaway for every three successful giveaways. If you have a really good reason you can request more giveaway slots from support.

You start with 3 active giveaway slots. With every 3 successful "received" giveaways, you earn another slot.

If you delete a giveaway, you lose a slot.

Since you deleted two giveaways, you only have one available giveaway slot. Once your current giveaway is marked as "received", that slot will be available to make a new giveaway.

irockulisten, bobofatt - this in what I wanted to know, thanks!
Also thanks to DarkAlkaiser and heavenhairsixes for helpful answers.