You're using the same controls as me, so that's easy to picture at least..
Try pushing the stick more to 2'oclock. When I want to really get the ball moving that way,I almost hold it dead sideways (3'oclock). You just have to make sure there is still a slight angle, otherwise you'll end up bowling cross-seamers. Which are worse than useless (You don't even get skill points for taking wickets with them). You will also get more swing by bowling fuller. The only problem with that is you'll end up bowling a fair few full tosses, and if the batsmen in your game are anything like mine, full tosses tend to end up somewhere in the vicinity of the hot-dog van at backward square leg.
The easiest way I would say to raise your inswing skill, is in the short formats. Bowl lots of them in T20's, or the 2nd innings of 40/50 over matches.Basically any time where the batsmen will be more aggressive, and therefore more likely to get out. You CAN raise it quite quickly in 4-dayers aswell, but that involves bowling nothing but inswing for overs and overs at a time to ensure you get the skill point you want.
Raising bowling skills can be hell when they're low, as it'll take a long time before you even notice any increase in-game. But stick at it, and hopefully this helps you out.