There could be several causes to this problem. Lifestyle is one of the main ones. In your teen years you may have had a healthier lifestyle. Smog, allergies, illness, fatigue, mental and emotional state, daily usage, training, etc. all change from your teenage years thus affecting your voice. Try looking up tips for vocal technique -- they should all cover how to relieve these problems or cope with them. Another factor that may be the cause of your "hoarse throat" is that you may have damaged your voice somewhere along the line. If this damage is not permanent, i would reccomend resting your voice alot and follow proper techniques like warming up. DO NOT try to reach for any notes that you are in anyway uncomfortable with. Once you are "healed" so to speak, you can try to COMFORTABLY increase your range -- but this should only be done very slowly, making sure that you are not hurting your voice. It is best that you see a proffessional vocal trainer to determine your circumstances. There may be other causes to your dilemma, but would probably be categorized under the ones i mentioned. I hope that this information was accurate for you and can help you. =D