i can completely relate as i too am a fighter or just finished fighting. There is no way to overcome the fear except to keep on keeping on. I am no doubt older than you 39 and have been training mma for little over 2 years with no previous fighting experience. I did this as a personal test with no future hopes for the sport. I learned several things. 2 weeks before my first fight got injured and had to have neck surgery. six month later the comeback was difficult but incredibly rewarding. The first thing to remember is you WANT to be getting your ass kicked in the gym! this is how you get better, If you are not it is time to move to another gym.
In my case i fight at heavyweight and was getting the crap kicked out of me by a 155 pounder 4 time golden glove champ. and yes i too was brought to tears when i was knocked out in the gym during a sparring session just as i began to feel like i was making progress. It really shows you how much you have yet to learn.

Remember you only cry in those moments when you have left it all on the mat!!! if you were not dedicating 100% to what you were doing you would not be crushed when you fail. this is not a moment of weakness this is a moment to recognise that your are training as hard as you should be.

the next thing to remember is when i was going into my first fight my coaches had more faith in me than i did. they put me against the number 9 ranked amature heavy weight in mn. this was my first fight and to be thrust against a ranked fighter can be intimidating. then i remembered something, I get my ass kicked every day by some of the states best fighters! and i train harder than 90% of the guys in my gym, I gave a full 8 week fight camp with clean eating and close to 20 hours a week of training boxing, jiu jitsu, muay thai, wrestling and cardio. YOUR TRAINING BUILDS YOUR CONFIDENCE! if you have given it everything in the gym you will be nervous but confident in your fight. if you are a week out and are saying man i should have done more sprints, i shouldn’t have eaten so much last week then you know you are not ready! you did not prepare properly and therefor will be scared. if you done everything right at the end of your fight camp “you will have the eye of the tiger” you will be focused, pissy and mean. you will not want to train another minute, you will be itching to get in the cage and bang! nerves are a part of the game, fear is not, if you are fearful you just need more time, this does not mean you are not cut out for it or that you are weak just need more time to hone your skills period, end of story.

this sport is so mental! do a search for mental toughness and practice it every day the difference is winning and losing as i can atest to. I did win my first fight and at age 39 with a record of 1-0 became the 9th ranked heavyweight in my state. I simply would not be denied, i took everything he had and quitting never entered my mind, i was cut, bleeding and one eye closed in an all out war and i made him quit i scored a 2nd round tko against an undefeated fighter. I was literally too tired to tired to celebrate but no way i was quitting (i was right mentally for this fight).

My second fight was different, i had nothing to fight for i had already accomplished everything i wanted in the sport. i was ranked, in better shape and my all around game was better but i only took the fight as i felt i was expected to. like i said this was just for fun for me, a hobbie. I really didn’t want to fight and it showed i lost to strikes on the ground to a far less fighter. i was superior in every way but mentally was not in it i was looking for a way out. yes it is frightening fighting in front of thousands of people but remember you are the one getting in the cage, the people are there to see you win or lose. Mma fans are awesome especially at the amature level. I felt worse about myself not leaving it all in the cage then the fans did. they told me good job even though i lost. YOU ARE NOT DOING IT FOR THEM this is for you. keep working hard, and add the mental preparation into your training. if your afraid this is not telling you to quit it is telling you that you need more time. you will know when you are ready and do not take a fight until you are.

good luck
Jason

p.s. there is no shame in asking your sparring partner to turn it down a notch so you can work. it is equally important to be able to work your movement as it is to prove you can take a punch. your coaches should know this and be monitoring this. at no point is it ok for a superior teammate to hand out a beat down in sparring. your teammates are there to help you. if this is not the case in your gym i would consider another gym.