A college student needs advices!

Hello everyone, I hope you all doing well.

Firstly, please excuse my bad English as it's not my mother language.

I'm a 20 year-old college student in my second year at a faculty of veterinary medicine. I found myself don't like my study as much I like programming and its related stuff. So, I want to learn programming (from the beginning as I've never studied it) and I'm willing to ba a life-long learner. My questions are:

1-Can I learn programming beside my veterinary study or I have to abandon one of them?

2-To be a professional programmer and qualified for jobs in big companies and businesses, do I have to study computer science and programming in a formal collage or the MOOCs are enough?

3-Is programming nowadays a good source of income (so I'll not regret abandoning veterinarian job)?

4-Are there any other advices I should take?

Thanks.