Could you run codes and give us that info....it would help us help you. By the way welcome aboard. Sounds like it is in limp mode, you could have other issues such as knock sensors/etc. but without codes don't know...
Hi Robin...welcome to the Forum
Have you tried a different brand of coil as the replacment one may be defective?
Alternatively, it could be spark plugs in addition to the coil that has failed.
Let us know what you find
Cheers Trevor