If you don't have the time or desire to do whatever is being asked of you, say, 'no.' Even if you want to bake those cookies for your kid's fundraiser or take on a new freelancing gig, sometimes you just have to politely decline until you do have the extra time. The other party may be disappointed, but it's not the end of the world.
If you're receiving fewer assignments, this could be an indicator that there was a decision from upper management that you shouldn't have as many responsibilities. Whether that means your employer has lost faith in you or that your job may be in jeopardy, this is a sign that you should start polishing up your resume.
I've interviewed people where their response was literally one word for everything I asked. This didn't help me get to know them, nor did it sell me on their skill set to help my company achieve its goals. I got nothing from them, which meant I had no way of knowing if they were really a good fit in the company.