As someone who has worked with lots of teenage parents, I worry whether you really want this baby for the right reasons.As PP said it sounds like you don't want an abortion but not necessarily like you want a baby either? You sound very confused and you admit you keep changing your mind.
You speak about the baby in quite a disconnected way such as when you speak about 'getting rid of it', and you say you never wanted a child before becoming pregnant.Do you like children, and have you had any experience of being around or looking after babies and children? Do you feel like you want to care for, play with, educate, transport, prepare food for, supervise, love and have ultimate responsibility for a child for many years to come?
I am not particularly pro-abortion in general, but even i think you MUST to be able to give this baby the quality of life and quality of parenting he or she deserves if you are going to go ahead with the pregnancy.
Look around you at parents in the community you live...spend some time with friends/relative's children and see how it makes you feel...could you imagine yourself coping with/ doing/ enjoying the things they do All day every day? Constant feeding, changing, cuddling as babies, constant chasing around toddlers to make sure they don't hurt themselves, making 3 meals a day for them every day, staying up all night when they are ill soothing them and reassauring them with barely any sleep yourself? School runs every morning and every afternoon for years on end? None of us are prepared for the intensity of all that really, and many mums younger, older and inbetween do a great job of it all every day, but just something to think about, as whilst you have yyour own mum for support, as the baby's mother alot of that stuff should/will still be your responsibility.Even with people to help out, to be a good mum you would still need to be able to always put your child's needs before your own, and that WILL mean missing out socially, financially and sacrificing alot of your personal time.
Having a baby is in many ways for many people the most rewarding and overwhelmingly joyous experience they ever have, but sometimes being a parent to a continually crying baby, a toddler who is having a huge tantrum when you need to get out, or a child who won't go to bed and let you watch TV, feels like being a 24/7 servant, and it will test you to the limit sometimes.
The decision can only be yours, but if you DO have this baby then don't do it to improve your mental health (it could possibly do the opposite) to please your mum, or because you can't face the medical process etc of abortion.Do it because you feel some sort of readiness, excitement, love and connection to at least the thought of having a baby and then a child, which is something that can hopefully grow and develop over time xx