Anxiety issues. Any suggestions?

Hi i am suffering from anxiety issues.. my heartbeat goes fast when i have to do anything.. overthinks a lot thats why ended up doing nothing.. always have doubts after completing the day to day work like i have closed the door or have i collected everything.. nothing is left.. moreover i feel like while driving the car coming from behind will hit my car.. hesitate to do anything.. i always think that people are watching me.. find it hard to sleep sometimes. Although my body became weak.. at night i feel like i can conquer everything but with the sunrise i feel anxiety and an unknown fear thats why ended up doing nothing. I dont know how to deal with this. Do I seriously need any help or its just matter of confidence? Any suggestions? Thank you