Erection issue. Causing these issue?.

Hello i having this erection problem like i am not able to get erection without watching something like porn. And erection is only lasting for few seconds and it becomes soft. I had varicocele grade 1 in 2021 and i saw a urologist again last week he checked through physical examination and didn't find anything like in varicocele. He gave me a tablet called Revel 100 mg, containing Mucuna pruriens extract 100 mg for 15 days and he asked to take testosterone test also. I am worried right now because of this issue. Age : 25 Weight : 100kg Height : 160 cm. I am in obese state. Is obesity causing these issue? . If i loose weight will this issue will be resolved. How can have a good erection and strong. Symptoms i have: Gained more weight. Taking time to build muscle eventhough going to gym. How to solve these issue.