This is your first grow, right?
Certain things may have been off a bit here, off a bit there. And the result is not what you expected or where told.
No biggie, I am only on my 3rd grow and honestly my first grow looked just like yours. Yeild was alright but not enough for the struggle, but each grow since has been better. I'm starting to know what I'm seeing, and what to do. I'm still learning of course, but I'm taking my results with a grain of salt. I'm not going to produce the same as a 600watt hps in a 4"x"4 tent. But we should be able to maximize one - 2 plants in the cabinet.
( tent provides two things we don't have, space for bigger grow medium ( pots ) and more room for lights/ growth. )
I don't think you did anything "wrong" the plant survived till harvest and you seem to have gotten some bud off it. The seed thing is tricky like 7dust and major pita is saying, it works but has to be done a certain way as you are forcing part of the plant to change sex. Seems like some tricky voodoo for a newbie, I wouldn't add that variable to my first few grows. I understand wanting more seeds, for cost saving etc. I know I haven't even bought seeds yet, but have looked into it and it's a bit intimidating to see prices for a few seeds.
I'm new too, but I mentioned this in my thread. I think you should LST and top your next one, just to try. It changes how the plant grows, it becomes more flat and bushy like you want.