Is Earth losing orbit?
What determines the Earth's orbital separation from the Sun is the total mass of the Sun and Earth, as described by Kepler's third law.

The orbital radius of the Earth is increasing because the Sun is gradually losing mass both by emitting radiation and through the solar wind at a rate of around 5 million tonnes per second (e.g. Noerdlinger 2008).

Any gain of mass through the accretion of dust or asteroids (by the Earth or Sun) is negligible by comparison.

This mass loss rate is only sufficient to widen the Earth's orbit by about 1.5 cm per year.