I have a friend who very clearly described to me these exact conditions, and he was completely stressed out as a result.
Have you encountered this type of situation before? How did you deal with it?
Obviously there's not way to tell from this post, but a persistent problem I've seen in software organizations is that the sales staff are not accountable to clients or co-workers for inflated or over-optimistic promises of features or release dates. When targets are not met, client meetings often end up with an implicit passing of blame to the (absent) developers. This is a poisonous cycle that needs to be broken. One firm I knew off addressed this by bringing disappointed clients to the firm's HQ to explain to developers which features/use cases had priority. Clients felt mollified and valued, developers got valuable feedback without feeling forced into a commitment or marketing role, and sales staff took greater ownership of the relationship instead of seeing their sales as one-off zero-sum transactions. Obviously, this was politically challenging and a difficult step to take for most parties within the firm, but it increased productivity and good will considerably. It was a small firm and for many cases this approach is not easily mappable, but with the right leadership it can pay rich dividends.
A recent project of mine was put on hold due to changing requirements and lack of focus. we waited for the client to bring the right people to the table. Then we redrafted all governing documents and got them reapproved, sometimes by new individuals. We made sure from the restart we had a feasible project with well defined goals.