A big pe**is experience

Hey Reddit,I am a straight guy, but lately I have been attracted to a guy. I really wanted to try sex with a guy so ended up meeting a nice guy.I am a fit and well-educated guy. I was also told that I am nice and even cute, but whatever...So, I met this guy and tried to have sex. It was my kinda first experience and at places it felt so awkward, such as kissing and trying to suck his big cock and/or when he tried to suck mine as well. I felt a bit uncomfortable, but I guess that is a normal thing, especially for an inexperienced guy like myself.He has a big cock. It was about 17-18 cm, and very thick (about 6-7 cm). Wow, it was too big for me. I really wanted get fucked, but it was hurting and did not know how to take a big cock.... he seems very disappointed, but i tried my best. I love hugging and that was the most interesting part. We were naked and I felt so great...Does anyone can recommend some positions for me if I want to have sex with him again so I know how to take a big penis and not to bleed and die from bleeding. I also do not know how to kiss with a guy. Lol. I also kept thinking omg what if he has some disease, such as std etc., especially when i tried to suck his cock, but i did not suck it... i was just scared...Any advice will be appreciated. Thanks.