Help?

Hello! I'm not very sure if this is the correct sub to post this on as it's my first time here, so I apologize in advance.

As of a recently, I realized my cat is losing fur on the tip of their tail, and seemingly is slowly becoming more prominent and is traveling. He's a male, 10-11ish months old and has no health complications, from what we're aware of. For the most part he's an inside cat, so is our dog. I only occassionally take them out for walks, and him less than our dog. So he spends a vast majority of his time in the house. We keep our windows open and the blinds up so he can sight see, he has a cat tree, and we've recently bought him a little feather toy to add among to the many self-stimulating toys he has (balls with beads, regular balls, mice, scratch post, boxes, etc.) We also play with him ourself and he makes fun out of playing with our dog.

Is there anything I can do to prevent his from continuing to lose more fur? We currently don't have the money to take him to the vet due to earlier car troubles, but if it proves necessary, we're willing to get him seen and treated. He hasn't shown any symptoms of distress, or has had drastic changes in behavior or eating and sleeping patterns. I do want to mention that due to his rambuctious/slightly destructive nature and my family's schedeule he's often left alone in my room until I return from school; it's quite big and has all his toys in it, but I can understand if it's stress-inducing. We've been letting him out more often for a few weeks, so nowadays he spends hours just running around the entire house anyways, but there are still times where he's stuck in my room. Unfortunately, I doubt i'll be change that factor, so if it is stress, is there any way I could entertain him while i'm gone?