Every item has a chance to break with every xp/gold tick you get during a round, if it breaks it will have to be repaired for a portion of the shop price at the end of a round. This is to prevent people from using really expensive stuff all the time, it is still possible, but it will cost you. Statistically every player should be able to break even with about a 40k total gear cost. This is a long term statistic, which means that you can easily lose like 20k with a bit of bad luck, but you will also sometimes get lucky and gain money. If you look at your inventory on the cRPG page it shows you the gear cost, I recommend you to try to get that around 30k to be sure to not lose money and perhaps even build a bit of a buffer. If you have like a 50k buffer you can try out using equipment that costs 40k.
You appear to be playing a horse archer, which is a very expensive class due to the horse and multiple stacks of arrows. I believe arrows have an added breaking chance because people often use multiple stacks of them so they break often. Apart from that weapon breaking chances depend on the amount of wpf for that weapon. If you have somewhat low archery wpf still, the weapon will break more often.
I did a quick guesstimation of your gear and it appears you have about 40k total cost. In theory this should allow you to break even, but arrows break more often and you don't have much of a gold buffer. So in the short term you will go broke for sure. I believe repairing is done automatically be default, but if you go broke it won't repair automatically as you don't have the money. In that case you need to manually go to your items on the webpage and repair them. This can be really annoying as it takes a long time to update ingame, unless you rejoin the server.
You should try to get your gear cost down closer to 30k. Your armour is quite heavy for a horse archer, armour weight reduces your archery wpf. I recommend using something in the 3,5k-4k cost range. Your sword, the Espada Eslavona is one of the more expensive swords and as you have a bow, you probably don't even use it that much. I think some other good but cheaper choices are a Scottish Sword, Short Arming Sword or the Military Sickle.