Its good to be able to talk through anxieties you have is there any counsellor you can speak to, you had a trauma when he died and it takes time to accept that,talking to someone brings it out , make sure you are busy have friends, keep your thoughts positive, try not to look back too much as it will make you anxious., what about sport and exercise they help a lot..you are here take a look at the forums and groups we have teen forums ,you can make friends with other members who you will be able to help ..Good luck
anxiety is terrible when you don't manage it :)