You are making the classic mistake many planners make. You are not accounting for the travel time. Also, you are trying to see too much.
For example, you plan to drive to Bath, taking in Stonehenge on the way. This will take up most of your day. When you arrive in Bath, you won't have much time to see the city, just find your hotel or B&B, a place to park, which is an issue there and plan for the next day. The next day you plan to see Bath and drive to Cardiff.
Suggest you do some research and determine about how long that drive will take. Also, consider parking and finding your place of lodging. How much time will you have to see Bath. We spent three nights there, including a full day visiting Bath, the second day we drove to Glastonbury and Wells, the next day we drove to Cardiff and did visit an Tintern Abbey and a nice castle in route.
You aren't planning to visit interesting sites that are on the way. Next you plan to leave Cardiff and go to the Cotswolds. Are you planning to visit the Cardiff Castle and museum? That will take about half a day. I don't think you will try to see the wonderful other sites nearby like the Museum of Welsh Life or another castle.
It gets worse, you plan to see Oxford and drive to York in the same day. You won't see much of Oxford.
Do some serious planning and reduce your planned sites.
Here is what we did for our 28 days in South Wales and England in 2017.
28 days in Britain and Celebrity Eclipse home
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