"I didn't speak"I didn't spoke (?)
Concerning the accent, mine is quite okay according to the people I met (native english speakers or other nationalities), I do not have an "british" or "american" accent but at least I do not have the french one. And I developed it by listening to a lot of music in english and singing them again and again (pretty badly, I have to admit ) in my room. I'd say that listening to a lot of english would help. Maybe you can try to put podcast/videos in english as a background noise when you are doing something else (cleaning your dishes for example ?), without trying to focus on what is being said, so you would get used to the accent without paying attention.
That's the method I used for german. I always had german tv programs as a background noise for a whole summer, and even if I didn't understand what was happening in those shows (show ? ) I lost part of my huuuge french accent.