I'm sorry that no one who can help has posted yet, but please try to be patient since this is a bulletin board most of us visit when we can find time.
(I haven't been in your position. Unfortunately, my auto-immune disorder, which couldn't be pegged definitely but is similar to Lupus, prevented me from having children. I had four miscarriages but wasn't diagnosed for almost 14 years. I taught middle school and high school students for many years, so I have heard of young women in similar situations.)
I don't know what your town is like or what services are available. You are wise to be clear about your relationship with your mom. I'll propose to you that you could benefit from an older mom who can be your "coach". Better yet if your coach has an immune disorder or some other physical ailment and has been successful. A mom like that could be found through community agencies (United Way has contact with many agencies), religious organizations or houses of worship. You'll want to start looking now for such a coach. It'll mean you will need to think about your physical needs and your child's, but also think about your own approach to parenting. The library will have lots of books on this, but I bet you've been thinking about this yourself.
You'll need to listen carefully to your possible coach's approach too, to make sure you're on the same page.
I hope this will give you an idea for a positive path to take, whether it's based on my suggestions or on your own. Please let us know how you and your baby are doing!
P.S.- I just read your profile and see that you're in Ireland. Most of what I wrote would work for you, but "United Way" is an organization that is made up of organizations which provide services such as blood banks, help for people with disabilities, etc. I don't know the equivalent where you live, but that needed clarifying.