Hello Peachy,
Managing the emotions of both your son and husband is very delicate situation for you.
Your husband's expectations regarding the level of study that he is requiring from your son is not feasible, unrealistic and very unfair.
If these expectations are not addressed and revised quickly, this will most likely lead to resentment and feelings of rejection, being less-than and self-confidence/esteem issues for your son, and may possibly damage their relationship now and in the long term.
I think that you will need to understand
WHY it is so important to your husband, for your son to attend Oxbridge, is it:
- son following in his fathers footsteps?
- pride?
- cultural?
- reliving/correcting his own childhood ?
- extended family expectations and pressure?
- keeping up with the Joneses?
- Or some other reason// combination of all of the above
Until you can understand the reasons for your husband pushing so hard, it will be difficult to get him to change his view point and not be so demanding.
In the meantime, make sure your son is doing things he enjoys and things that boost his confidence.
Best of luck.