Oh dear god, I hope this is a troll post.
If it isn't, then here's some advice. Having a baby now, would hurt you and your baby's life. Firstly, looking after your younger siblings does not in any way qualify you to be a mother, it's probably the hardest years of a woman's life when they first become a mother. Are you really ready for that? You've only just done GCSEs! Surely you want some more life experience, travel the world a bit, meet new friends, go to university, go clubbing, marriage etc? Having a child now will tie you down for the next 18 years at least. You won't be able to really connect with people your age because you'll have a baby to look after, which will alienate you because I doubt anyone your age will be able to understand you having a baby so young and you also won't have the time to have a proper social life. You won't be able to really do further education unless its part- time, and you won't be able to do an internship/apprenticeship. So, in 10 years time when you want to get a job, you'll be stuck as a waitress or cashier to start your job career. Even travelling with a baby you'll be tied down and with only your partner's salary will it be enough to live that lifestyle?
Is this your first proper relationship? In 10 years time when he's getting older will he still be attractive? Will you not look at guys your age and have regret? What if he leaves you in 5/10 years time? You'll have to have part-time work, be on benefits possibly and move back in with your parents. Without your partner your life would completely fall apart, do you trust him that much?
Lastly, people already think its weird a 16 year old hooking up with a 46 year old and they're going to think its even stranger when you have a baby. Think about what your child's friends and their parents will think when they find out about that age gap.
Look at your life, it wouldn't be healthy at all