Help/advice

Hello I am a 4th engineer at currently gas tanker. I feel insecure and incompetent at my job. I had an awful internship I wasn’t speaking their language and I don’t want to give all the details but I couldn’t learn anything. I completed 2 contracts as 4th engineer,one bulk carrier one gas tanker.My first contract I was like doing my cadetship now I finished my 2nd contract but I feel still incompetent. I am hesitant about taking actions when I see a leakage somewhere and etc. I am afraid to make a mistake and cause bigger problems. I want to be competent and trustworthy at my job.Plus I am easily distracted and forget things easily.Are these only specisl to me or are there people who went through this process and succeed.I need this job right now but I feel like I have to be good at it otherwise it makes me feel miserable.Going to ship right now makes me feel so anxious because I remember the mistakes I had and afraid to do new ones again. Any advice