How do I pray to conceive without despairing in the waiting?
Ask directly, and let yourself grieve each month you must ask again. Waiting is not passivity, and it is not a verdict on your faith. Do not let anyone tell you a better attitude would have worked by now — that is cruelty dressed as piety. Say the wanting out loud, and the exhaustion out loud. Ask for the child, and for the strength to keep living a life in the meantime. Both belong in one prayer.
The tradition's word is pekidah — a being-remembered: the way it speaks of Sarah and Hannah, held long, then remembered.
From the sources “He settles the childless woman in her home as a joyful mother.” — Psalm 113