At your age, most people take on a job just to earn money and then find out it is not for them. You need to find something that you'd really like to do and maybe go into an apprenticeship. That might mean a little less money at the start, but if you still live at home, it might just give you a chance to concentrate on looking for something that just right for you.
Being jealous of family members is not really jealousy.. it is generally envy.. but look at it this way - your just starting in life and on your journey you will find yourself, your taste in women, the right attitude towards life, and have plenty of time to 'find' yourself and to be able to share the same interests. This all takes time, so don't be in a hurry to jump into something you are not sure of just because you are a little dissatisfied with your own life at present. This is the time to get to know yourself and grow, and that takes time, so be patient.
I would also suggest that you tell Mom that you are going to try to handle your affairs on your own and will ask her for help if you think you need it, but that you'd rather take charge as best as you can. Mom's forget that their 'babys' need a chance to grow up and make their own mistakes and develop the strength to deal with them as they come. I think the more steps you take toward independence, the prouder your grandma and mom will be.. even though it is sometimes hard for them to 'let go' of the feeling that they have to protect you all your life.
Go out and visit friends your age, or make new friends. Don't turn into a 'wallflower' because you think that mom and grandma need you around all the time. Show them that you are growing and need a little space to be yourself.
Let us know what type of job you might be interested in, what you'd like to do with your spare time, hobbies, etc. and we might be able to give you some hints on how to achieve your goals.
Good luck dear, and keep us posted.

It's time you get into the 'driver's seat' and take charge.