wysiwyg switched to tinymce

default wysiwyg editor was gone all of the sudden and tinymce editor shows up everytime i want to edit some text for custom fields (wysiwyg custom field). Is there anyway to just switch back to default one?

now there’s no “text” tab i can click on so everytime i put code in (ex. contact form code), instead of showing the form it’s showing the actual code in text.

Could you help me please?