Single word for expressing "those which I am dependent on"

You could consider using dependee as it means:

(programming) An agent that is depended on by a depender, the target of a dependency (used in agent-oriented programming)

There is a usage note:

Technical term, not widely used in software engineering outside of agent-oriented programming but finds some use. In agent-oriented programming the antonym is depender, though in general usage the common term dependent is used instead. There is no common language equivalent for dependee, however – other metaphors are used instead, such as parent/child. The circumlocutions “A depends on B” and “B is depended on by A” are much more common in general use than “A is the depender, B is the dependee”.

[Wiktionary]

In wider usage, patron, benefactor, supplier or guardian could be appropriate options. In your more specific instance, I would suggest Provider:

1. a person or thing that provides. - dictionary.reference.com (emphasis added)