Dotty is right, Femoston is much better tolerated so you might want to try that. Alternatively, you could consider the Oestrogel/Utrogestan regime which is what many MM members use.
A lot of women fall over on the progesterone part of HRT even if they are not progesterone intolerant per se and norethisterone is one of the worst offenders.
Take a look at the treatment section on here to get some ideas.