Honestly, your thoughts seem disorganized and lacking clarity and resolve. Your text reads like someone trying to persuade themselves that you should want a vasectomy or looking for someone else to tell you what to do. You seem to lack maturity.
You also seem to be in a place in your life where STDs should also be a concern and you have plenty of other options for avoiding pregnancy.
I think you're too young.
You shouldn't have anything to worry about. In my opinion cryofrozen sperm and a vasectomy is the best and safest option for 100% planned pregnancy. I am surprised I didn't do it sooner.