why I lost my level?

From the FAQ'

Why did my level decrease?

There are two reasons why a decrease could occur.
Values are calculated based on the current USD prices of games in the Steam store. If a game lowers in price, the value of previously created giveaways will adjust accordingly, and this will be reflected on profiles and levels.
Certain games on our site are flagged as "No Value" or "Reduced Value". This is done manually by our volunteers, and therefore there might be a delay before these values are assigned. For example, a game might be included in a bundle on January 10, 2018. If on January 13, 2018 we flag that game as "Reduced Value", with an effective date starting January 10, 2018 (the day the bundle started), then giveaways created between January 10-13, 2018 would have their value reduced accordingly.

All of your giveaways are market not received?

How did you even have level 1 to begin with...?

Check under the sofa

oh FAQ... mission failed. 😑

View attached image.

Your giveaways are "Not Received".

Looks like level is not the only thing you've lost, and it'll be a bit hard to get it back without any giveaway slots. If you are eager to try to start again, create a support ticket, maybe they'll agree to give you some new ones, but I wouldn't exactly count on that.

Seems like one of your giveaways that were marked as "received" before has been now turned in to "not received". Either the winner realized that he broke the rules before and corrected the mistake or asked support to change it for not to have the game in their win list for some not so good reason.

I presented some games

I had level 1

thats not true