Learn English – Difficulty doing something or difficulty to do something

Your example is incorrect because your ethics is not the same as yourself, regardless of ownership. Even though values are an integral part of defining a person, they are not the same. An individual might change and is more than their ethics, and the same morals may be held by multiple people. You've suggested this yourself by acknowledging ethics as an external force.

Refrain is a reflexive verb and used intransitively. The definition encapsulates a patient already; the agent always holds back or stops itself. One never refrains something else, and we typically don't say I refrained myself because that's redundant. Note that I refrained myself is not really a transitive usage; it's an explicit statement of the complete reflexive meaning.

Archaically, refrain was used transitively as a synonym for restrain (meaning you could refrain someone else, not just yourself), but this usage has been dropped from modern English and is no longer correct.

I suggest using restrain for transitive cases such as your sample sentence.

In the case of "suggest", the two options that come to mind are:

I suggested going in my car.

and

I suggested (that) we go in my car.

You cannot say directly "to suggest someone something", nor can you say "to suggest (to) do something".
See further explanation on English Teacher Melanie and more examples of the correct usage of this verb on Oxford Learner's Dictionaries.

Using "advise" doesn't sound right in this context. If there were a third person saying it, the sentence could be:

He advised us to go in my car.

More correct usage of "advise" on Oxford Learner's Dictionaries.