beat up in sparring

[boyla]

Solar-Plexus takes the wind out of most amateur trained fighters.

Agree if you want to get better you have to fight better opposition.

[Gray Lion]

With just the information you have provided, my answer is llimited to recommending you first search your inner self to see if you still have the drive, the fire, and the spirit to win.
Second, I need to ask...have you just been sparring with guys at your level for a long period of time and become stale? I have two boxers I call the "Pattie Cake kids" because they always spar among themselves, get in the ring and do the same thing. I can close my eyes and hear the same rythem of punches being thrown....in short, they are not learning anything..they are comfortable fighting only each other...will never progress...have no interest in taking on a new sparring challenger....so I don't waste my time with them anymore...it's their money...and if they want to piss it away pretending to learn boxing...thats fine.
Third...go back to your basics. Sometimes you develop subtle flaws or bad habits you are not aware...have a coach or a good sparing partner work with you and let them critique you.
Age, physical condition are important...but rermember--boxing is called the sweet science and many an older boxer has proved time and time again, that skill, experience and the heart to win will overcome.