Mathematicallly, yes... but it'll be difficult!
If you've taken 1 year's worth of college credits, it's about 30 credits.
30* 2.9 = 87 quality points.
To have a 3.5 in 2 years, you would need (90*3.5=X) 315 quality points.
That means that you need to earn (315-87=X) 228 quality points in 2 years.
That comes to 114 quality points per year.
X=114/30 ... X=3.8
You would need to maintain a 3.8 GPA in order to do so.
Here's how you figure out what GPA you'd need to raise a 2.9 to a 3.5 if you've taken one semester, have 4 semesters left, and take the same number of credit hours each semester.
(2.9 * 1 + x * 4) / 5 = 3.5
x = (3.5 * 5 - 2.9 * 1) / 4 = 3.65
You'll need almost all A's to pull it off, only a couple of B's. This is online college - being sick doesn't keep you from going to class or getting most of your work done. You can do it all from bed.
anything is possible, but you need to work for it to try and get it there. Maybe try bumping up those babysitting days because if you want this , your gonna have to reach higher to get higher. Just keep thinking positive, and things will hopefully work out.
Being as college doesn't get easier to further you go along, it gets quite a bit harder each succeeding year - along with the fact that you'll find other lame excuses to blame your poor performance - it seems a rather impractical expectation on your part.