HI SalliWW,
It would be best to have all your similar keywords in one campaign with separate ad groups. This will allow you to better manage your budget and ensure that your ads are being shown to the right audience. Having multiple campaigns with similar keywords can lead to competition within your own campaigns and result in wasted ad spend.

In terms of exact match, Google has recently changed the way it works, but it is still a powerful tool for targeting specific keywords. You should consider using a combination of broad match, phrase match, and exact match to ensure that you are reaching a wide audience while also targeting specific keywords.

Additionally, you can use negative keywords to ensure that your ads are not shown to irrelevant search queries. This can help you to further optimize your campaigns and improve your ROI.