Day-to-day meditation and the quiet mind

Saṭipatṭhāna has many levels, such as Sīla, Khaṇika Samādhi, Taruṇa Vipassanā, Balava Vipassanā, Ariya Magga.
Sīla, Khaṇika Samādhi and Taruṇa Vipassanā do not require a quiet mind, so the practitioner can do it in day-to-day life.
Upacāra Samādhi, Appanā Samādhi (Lokiya Jhāna), Balava Vipassanā, Ariya Magga (Lokuttara Jhāna) require a quiet mind because...

1. Upacāra Samādhi mind and Appanā Samādhi mind (Lokiya Jhāna) know only one object, unleashing five string objects, but Sīla and Khaṇika Samādhi minds know those both five string objects and unleashing five string objects, so they can't upgrade to be Upacāra Samādhi mind, Appanā Samādhi mind.
2. Balava Vipassanā mind knows only the last vanished Vipassanā-Mind and it's three characteristics as object, but Taruṇa Vipassanā knows five string objects too, so it can't upgrade to be Balava Vipassanā.
3. Ariya Magga mind (Lokuttara Jhāna) knows only Nibbāna, but Sīla, Khaṇika Samādhi, Taruṇa Vipassanā, and Balava Vipassanā minds know the other objects too, so they can upgrade to be Ariya Magga.

So, the definition of the meditation is:

All the wisdom of one who has attained (appanā), is, wisdom by means of development.

The meditation is the cessation of all suffering, not only the present suffering. If the meditation is not strong enough, it can ceases only the present suffering and keeps the future suffering going on.
Daily life Vipassanā is good and the practitioner should do it, but Nibbāna is the best, so only doing good is not enough to enlighten Nibbāna.
See KN Paṭisambhidāmagga, Visuddhimagga, DN Mahāsatipaṭṭhānasutta.

How to manage overthinking?

Overdue thinking and late thinking can stop by planning.

Over wrong view thinking and wrong decision can stop by right view thinking practice.

Over five-strings thinking can stop by upacara/appana-jhana and can cease by vipassana.

Over right view thinking (vipassana-upakkilesa) can relax by upacara/appana-jhana.

Overall suffering can cease by Nibbana. And the practitioner can attain Nibbana by adhisila+adhicitta+adhipanna.