Can you move past the beginner phase with 30 minutes a day?

I feel stuck in my meditation practice. I practice about 30 minutes a day. I’m calmer but I don’t feel like my mental health has improved that much.

I see many describing how meditation changed their life. Meanwhile I’m not seeing that much of an improvement.

I work full time and I’m going to school part time. I work out regularly and try to get 8-9 hours of sleep. Anything less and I’m horrible to be around. I get maybe 1-2 hours to myself a day. I would like to improve my mental health but I don’t have a lot of time.

I would like to get to the point where nothing bothers me. I read about monks in extreme pain and it doesn’t bother at all. Is this a common achievement? Or is this something only masters can attain?

Are my goals realistic? Or should I temper my expectations?