You only had 12 months to legally drive in the UK on your US licence after you arrived in the UK in 2012.
Once those 12 months were up, if you had not passed the UK tests and did not gain a UK licence, it has been illegal for you to drive in the UK on your US licence. If you wish to drive now, you will need to apply for a UK provisional licence and will be treated like a learner driver until you have passed your tests and have a full UK licence
Therefore, if you have driven on your US licence AT ALL since 2013, you have been driving illegally, without a valid licence and and without valid insurance.
So, if you wish to hire a car in the UK, it will have to be in your UK spouse's name only and you will not be legally allowed to drive it.