If you are going to stick with road cycling, then NO, you absolutely did not over buy. I ride a 2008 Roubaix, when I bought (used) it I was 220#. Now almost six years and 35,000 miles later, I am 196#, all my blood numbers have improved and in the last six months even my blood pressure is finally improving and I have dropped one med for this. And my Roubaix? Still rolling. I’ve bought new wheels for it, regular maintenance of course, but the frame has held up fine. And I rented a new Roubaix a few months ago, they are great bikes. A quality bike with quality components will last a long time, the components are amazingly reliable, and once you have it dialed in and fitted you will be amazed at how far you can go.
I hope you find you enjoy it and stick with it. Hopefully your husband will support you in this. FYI my wife rides about 25% of the riding I do, but I bought her a similar level bike to yours (Liv/Giant Avail Advanced 2), just because a better bike is nicer to ride, shift and brake, and lighter weight to lift in and out of the car. She’s had it four years now and is still riding it a couple times a week, she has lost weight as well, so I call that money well spent.