First of all Saturn posited in Leo is not good as it is sign of Inimical Sun. Saturn in 10th house brings delays and obstacles. Saturn is the planet of hard work, but in inimical sign even hard work doe not pay. Retrograde effect would be more when Saturn becomes Saturn becomes Retrograde during transit. Saturn being a malefic planet would give malefic results more strongly. Debilitated Saturn in Navamsha is not good , you should do the remedies of Saturn for benefits.
Saturn is not the planet of Denial but delays. Therefore it will give results after lot of obstructions and delays. Saturn is a karmic planet in the karmastan therefore aadmi se pura karam karega before it gives results.
As Saturn is debilitated in Navamsha but retrograde as wll in Natal chart, it will give you stability in life late in life can be 38 years or even 40 years. Work hard and with full determination and you will get your goals. Saturn will help you achieve your objectives.