Correct, this is definitely very draining. My solution was to add a marketing wing to my consultancy. That marketing wing is hyper focused on launch and growth strategy. A high percentage of my clients purchase this "upsell" and the projects go much better post launch. Win/Win. More successful projects = better case studies + more tech work on those successful projects + more marketing work, etc etc etc. It becomes a virtuous cycle.

If you don't feel up to adding this offering, partner with another agency who already does it.