You have mixed a dilution that is twice as strong as dilution A...which itself is twice as strong as dilution B.
There is no way to make this mistake if you actually read the side of the bottle, so I don't get it. The instructions are very specific; more so than any other Kodak developers (which have directions with only simple pictures and temperatures). You need to wake up and read the directions when getting your chemicals ready!
Next will probably come all the posts about how confusing HC-110 mixing is...but it is not. You have concentrate, stock, and working, like any developer. Concentrate is just the same as any powdered developer mix. You mix it with water to make stock. It adds volume, just like powder. Stock is just the same as stock from powdered developer. Working is made by diluting stock, like with any developer. There is a ratio of concentrate to working solution to water when the lettered dilutions are stated (such as 1:15. A and 1:31, B, for instance). There is also a ratio of stock to water when mixing instructions are stated (1:3, A and 1:7, B, for instance).
What you can do is to realize that your custom stock is not only twice as strong as twice as strong as dilution A, but half as strong as the stock should be. (Stock should be 1:3 concentrate to water, A.K.A. 1/4 concentrate. You have a solution that is 1:7 concentrate to water, A.K.A. 1/8 concentrate.) Therefore, if you simply use twice as much of your custom stock it as is recommended for any lettered dilution, to make the same amount of working solution, your working dilution will be fine.
For instance, if you want to make 8 oz. of dilution B, you would normally use 1 oz. of stock, and 7 oz. of water. Now, you will use 2 oz. of your custom stock, and 6 oz. of water.
Your custom stock will last. Keep it in an air-tight container and it will last a very long time.