I feel ya! I'm a multi-passionate solopreneur myself. However, there are some things you may want to ask yourself before combining (or not combining) your businesses:

1) Do they both have the same target market?
2) Is there a need or problem in this market that would need a realtor/interior stylist combo?
3) Would this dilute or enhance your existing brand?

and probably the most important one:
4) What do you ultimately want to be doing in 1-5 years? Realtor or Interior stylist?

I can't say that running two businesses/brands will be easy when it's just you (or with a partner), but it can be done...and sometimes necessary depending on how you answer those questions.