The nuclear family is a relatively new western invention. The idea that your life romantically and supportively should be based around a single partnership, largely to the exclusion of all others, is actually quite a strange one.
Recently I had someone lecture me on the wisdom of having more than one source of support in my life. Their argument was that by not allowing a single partner to be the centre and source of all my love and support I was showing that I was not mature enough to be truly open to the fullness of partnership.
Is this truly the ultimate state? The natural human state? One where a single person is required to meet me in every way and I am required to match them in all regards. You and me against the world!
Human societies evolved in much more networked communities and in most other cultures large family dwellings and communal structures and bonds are the norm where support comes from many for many.
I must say that I see it as a source of strength that not all my eggs are in one basket. I feel that it allows me to seek support from steady ground instead of from desperation. It also gives me much more strength from which to support others. Loved ones in my life are not clinging to me as their sole raft in a storm instead I am a spoke in their wheel. This seems much more stable.