There could be variety of reasons for the loss in rankings. It depends on changes you've made on your website or marketing strategy. What type of strategy have you in place?
Best posts made by cian_murphy
-
RE: Help - my site is losing rank fast and I don't know what I've done!posted in Keyword Research
-
RE: How to avoid Google penalties being inherited when moving on with a new domain?posted in Intermediate & Advanced SEO
What is your domain authority, age and indexed page number?
If you've come to the point where you've tried every possible e.g. cleared all crawl errors, disavowed and removed 7/10 links on the spam score link scale in OSE. Remove pages that Google may perceive as invaluable. Then and only then would I go to a completely new domain.
I wouldn't use any content from the previous site either as your original site would most likely be given credit for the original source since it's in Google's index already.
As you can tell it would be a last resort for me to move domains unless I had very few indexed pages / valuable inbound links and a low domain authority I could easily build up again.