I built a website for global farmers,no money to cover the server cost now

Six months ago,I built a website for farmers,It would be a database for agriculture knowledge and farms.Although,the user number is going higher,the server cost is also going higher,after I received this month digitalocean bill,I found may be I cannot afford the DO server cost.What should I do now?I am applying Adsense,and tried to collaborate some suppliers.