"When is a project one too many?" when you feel the other projects you do are suffering because of the latest project you just took on. you don't want, for on

"When is a project one too many?" when you feel the other projects you do are suffering because of the latest project you just took on. you don't want, for one reason or another, one project to ruin some/all of the others. in your case, this sounds like what might be happening.