There are advantages and disadvantages to being a multi-instrumentalist. The most obvious disadvantage is hauling gear to rehearsals, performances or therapy sessions. I totally love my collapsible wagon by the way. Sometimes one instrument will languish while I am focusing on another. However, on the whole, playing several instruments has made me a better musician. Poly-rhythmic band music has helped me to explore Latin music and Middle Eastern drumming. Playing harp has helped me better read the vertical structure of piano music. When learning hammered dulcimer, it was more than a little difficult to read music and find notes on the rather baffling layout of the instrument. Memorizing my music helped me develop some mnemonic tricks for tunes on my harp. It also helped me to better imitate some of the ornaments and other nuances of the music. In addition, playing an instrument that is so different than anything I had ever played made playing harp and clarinet seem so much easier! Often, time away from even favorite tunes or pieces of music help me to approach it in a new way.
Consider stepping out of your comfort zone. Try a new hobby. Learn a new skill. Let me know how it goes!