Take a deep breath and count to 10.
You already have a problem (maybe) from jumping to conclusions. Read the posts here, no one has said you need a new engine. If you have the cars history and it does not indicate the valve guide seals replaced with the updated ones, it could be as simple as that, (about $400). You should have a dry and wet compression test and a leak down test as well as a pressure test of the cooling system.
It also sounds like you need the opinion of another tech. Look under the section that lists good techs in your area. If one isn't listed, this is the place to ask.
Since your records indicate frequent oil changes, that should weigh in your favor as far as the rings and valves go. TAke your time, go to another shop, ask questions here and usethe search feature to learn more. This is the best forum anywhere to get good,useful information.
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