This will be my second attempt in 2019, i think its common that every body feels at some point during their preparation that its not enough and of course the fear of failure and anxiety but we should not be distracted by these negative emotions, thoughts and feelings as they are temporary and also cause hindrance in our preparation. If you are continuously distracted by negative emotions i will advise you to pray and take a rest for some hours and relax and after that you will feel energized and will definitely study more passionately and with relaxed mind.
However, we should have complete faith in our ability and ourself, we should leave the rest on God and destiny.