I lost my contacts in my phone contacts list

hello. Could you help me. 2-3 days ago most of my contacts were deleted by unknown way. Few minutes before Ihad got some problems with WhatsUp. I couldn’t enter, because the phone memory was full. But in a moment What’sUp started to work, but most of my contacts were deleted. Before I got about 2000 contacts in my phone contact list, but now I have only 448 contacts. My iCloud is full also. That’s why the last reserved copy was made long ago ( about 5 years ago). please help me to get my contacts back. It is vitally urgent for my work.thank you