It can take a long time to get any real results when needle felting from scratch. I started to keep count for fun one day but got bored after 50 stabs!
But you can speed things up by changing your needle type and by using more than one. Plus, rolling the wool into a tighter ball or tube/sausage shape can speed things up.
Factors to consider:
1) type of wool - the staple length of the fleece will determine whether the fibres tangle quickly or not. I think Merino wool felts faster than say
2) type of needle - there are different gauges of needles which work better with different fibre. Eg coarser fibres need a different gauge of needle to finer fibres.
3) shape of needle - i didn't realise but the felting needles come in different shapes. So far I've used ones with 3 points (looks like a triangle when you look closely at the tip and shaft) and 5 points (looks like a star).
The star shaped needle works quicker as there are more barbs on it than the 3 points. PLUS the barbs on the 5 point needle are nearer to the tip of the needle for some reason.
4) the angle at which you stab the wool can affect the outcome. I know you're supposed to stab straight on, but I also stab from different angles, making sure the needle is kept straight and not bending. By changing the angle you can concentrate on different areas.
To speed things up you could consider starting by wet felting the basic shape and needle felting onto it once dried. Although this feels like cheating, it doesn't affect the integrity of the piece.
I use leftover felt from my wet felting projects, stacking them together and wrapping the roving around them when I'm working on anything bigger than 2".
Now that you've caught the bug, I would suggest getting a set of needles - some shops sell three sizes in a pack so you can get a few for very little cost.
Hope this helps.
Either way, your flower is lovely.