Whats wrong with my dog???

Ok this is probably more my fault than my dogs. Maybe I should say whats wrong with my dog and I? I have a combination bulldog/mastiff a year old. He is the most stubborn dog I have ever encountered. I need to spend more time with him, but basically he listens sometimes when he wants too. At times he will get so hyper and want to play that he thinks I'm his play toy. I have never tried to encourage this behavior at all, but he was given to me very young like 5 weeks old so he didnt receive the training from his mom. The mom was too young to have him and had to be removed for her own safety case she was too young and weak to be a mom and she had like 10 pups. Anyhow, i guess my dog has an issue distinguishing who is the human and who is teh dog and when to listen. I have taught him to sit, but sometimes he will get in a mood when he is hyper and when I say sit he wont, he will play and try to jump on me or play tug with my hand!!