the cervical tear you describe does not sound like something that would impede a future birth to me. Scar tissue *might* slow down dilation--you won't know until you get there.
I suggest that you look into nutritional and herbal aids to resolving scar tissue. If you live near enough to a Homeopath, you might get an assessment--I used homeopathy once, years ago, to help resolve scar tissue in one of my fallopian tubes, and it did great. A homeopath is not going to do an internal/visual exam--but an interview that will help him/her to determine best treatments for you. And homeopathy is so very gentle that you can't possibly do yourself any harm with it; if you use the wrong remedy, nothing at all will happen. With the right remedy, you will soon feel the changes.
Good luck! I really don't think that there's any real need for worry.