Can anyone answer if it is really possible to learn, make it natural to be more relaxed, more happy in everyday, without taking medicine? I think I am more anx

Can anyone answer if it is really possible to learn, make it natural to be more relaxed, more happy in everyday, without taking medicine? I think I am more anxious than I really need, and can be more relaxed and happy. For example, I study part-time and constantly feel self-inflicted pressure to study properly, making study feel like burden than fun. Or I worry too much about minor issues like broken pump in the garden, finding a kindergarten for my baby, etc. In reality, I am doing fine: I have a good income, great wife and son, no major health issues, I already have a degree and my studies of maths are more for self-growth with room for failure. I understand it logically that I do not want to treat my studies as obligation and can enjoy the process, that I want to be more relaxed and resilient to small problems. But plain understanding does not turn me into a more relaxed personality, as it does not pierce deep enough into the brain. Is there a way to re-wire our brains for better attitude and happiness?