Hello aspirant,
As per your question i do understand the situation.
Since, you are interested in mathematics it is quite obvious you will be choosing mathematics as one of your subjects.
Physics is a subject very much related to maths.
So i would suggest you to go with chemistry.
Chemistry has wider scope range when compared with physics.
After bsc you can even go with msc in chemistry.
Chemistry stands more invidual strength.
Please choose whatever you are good at and importantly what interests you the most.
All the best.