I've cycled finasteride and propecia at times for over a year. Blocking DHT formation is great for hair growth but hard on libido, mental drive, vascularity, red blood cells counts, etc. You have to remember that DHT binds more strongly to the androgen receptor than does testosterone and has a much more profound effect on libido. Blocking it is great for some reasons but definitely hurts you in a lot of other areas.
If you find finasteride to be too strong you can always try saw palmetto or nettle root, although I would definitely give the finasteride a try if you get the chance. Run the EQ/SUST and run 25 mg. of finasteride ED. There could be a DHT rebound, especially if your inherent reductase levels were already high to begin with genetically, but I also suspect you may be about to wean yourself off or maintain with a lower dose long term and get the best results.