Waruna Maddumage

Do you have any advice to improve the convergence? Or at least any limits for monitors I can use to say confidently the solution is converged. 

My Mesh has a min orthogonal quality of 0.15 and 99% of cells have an aspect ratio less than 100 (a few cells around 200). My model is around 30M cells now. Since it is not the best Mesh, could this be a problem as well for poor convergence?