The controlling abuser aims to alienate you from everyone else in your life other than them. That way, your friends or family won't recognize the signs of abuse or come to your aid. Most abusers want you to be totally dependent on them and no one else. At first this may appear that your partner is just really invested in your life and your decisions, but it will slowly spiral into them being in total control.
It's important to take a good look at your life - is your partner giving you the freedom to spend time with other people - or is it all about being with them and doing what they want? You have the right to have other relationships - to spend time doing what YOU want to do, too. If you're feeling controlled or "smothered" that's a good sign of someone with an abusive personality.