Why my free 200$ credits are ending so faster like this (a reduction of 100$/ 2weeks/ 80gb ssd / 4gb ram)

Hello hi! im new to digitalocean and im enjoying the simplicity. now im using 4bg ram with 80ssd which is 20$/monthly. but im still using credits.

but im wondering that WITHIN 2 WEEKS MY CREDITS HAS BEEN DROPED FROM 200$–> 90$. im afraid that when i will start to be charged the real price it will be high.

and actually now im in developing stages of my websites.

i launched like 4 droplets to tests things but i destroyed all 3 and left with only 1 which im now using. and also i have only 1 snapshot which is below 2gb. all these things has happned within 2 weeks. but why these costs on my credits come down faster?

i need your fast help please cause i need to launch my website now but im fearing that i cant handle these costs which goes 100$/14days for 4gbram and 8gb ssd.

thanks for fast help!