You are a Scorpio ascendant. Currently you are going through Mercury Mahadasha which will be operational for you till 18 June 2017.
In your horoscope, Mercury is a Maraka / Malefic planet as it rules the 8th and 11th house and is posited in the 12th house. In no way you should be wearing a Mercury gemstone like Emerald / Peridot. Also avoid Venus and Saturn gemstones like Diamond and Blue Sapphire.
Placement of Sun and the lagna lord Mars in the 12th house don’t allow you to wear their gemstones, so avoid Ruby and Red Coral.
You may wear Moon and Jupiter gemstones like Pearl / Blue Moonstone and Yellow Sapphire / Yellow Topaz / Heliodor without any problem.
For the concerns you mentioned, I would suggest you a Yellow Sapphire / Yellow Topaz / Heliodor in Gold. Start wearing it in the Right Index finger on a Thursday of a shukla paksha in the hora of Jupiter.