Mass Effect assignment finished

Just finished Mass Effect for like the 3rd time because I lost all of my old saves due to a new HHD. The reason I did this was because I wanted to play ME2 with my ME1 character, and get alot of bonuses. I also heard if you do alot of the side quest in ME1, you can get alot of benifits and you meet alot of the characters again in ME2. Well the problem was, I just finished the game, and my plan was to do all the side quest after beating the campain, bad mistake. Right when I beat the final boss, I remembered, you cant continue doing more missions because the game ends, and your forced to do playthrough 2. I couldnt even talk to Conrad Verner, the fan in the citidel. I was also playing on hardcore and i didnt get the achievment for it becasue I didnt beat the majority of the game. w/e -_____-