TL;DR
We don't connect with God through practice alone — God wishes it, and bestows the meeting when our karma ripens. But God is always already inside us. We are iron with rust on it. Polish through meditation and good karma, and what was always there shines through. As Michelangelo painted it: God is always within reach. It is up to us to extend our hand.
There is a teaching in Sukhmani Sahib that sits at the heart of this question:
ਨਾਨਕ ਤਿਸੁ ਮਿਲੈ ਜਿਸੁ ਲਿਖਿਆ ਧੁਰਿ ਕਰਮੁ ॥
Nanak tis milai jis likhiaa dhur karam
Nanak, he alone meets Him whose karma is so pre-ordained.
— Guru Arjan Dev Ji, SGGS Ang 274
We do not connect with God through our practice or meditation alone. God wishes it. The meeting itself is bestowed — out of the devotee's good fortune and accumulated karma.
This sounds, at first, like fatalism. But the same tradition that teaches this also teaches something equally important.
The iron and the rust
God is always inside us. We are like iron that has accumulated rust over time. The iron is unchanged underneath. After some polish, it shines again.
Meditation, good karma, the practice of remembering — these are the polishing. They do not create the connection. The connection is already there. The practice removes what obscures it.
This is why the disconnection you feel is real, but not what you think. You have not lost God. You have lost the clarity to see what was never absent.
Within reach
There is a famous painting on the ceiling of the Sistine Chapel. God reaching toward Adam, their fingers almost touching, a small gap between them.
The gap is the teaching. God is always within reach of man. The hand is extended. Whether we extend ours back is up to us. That is free will.
So the question turns inward: are you reaching? Have you done the polishing? Are you sitting still long enough for the rust to come off?
The disconnection is real. The connection underneath it is more real. And the hand is always there, waiting.