Firstly, dont beat yourself up about not going to the gym, you will just upset yourself. Allow yourself to have a few days off and say... "thursday at 6pm ill be back at the gym", pack your gym bag the night before so your ready with no excuses. Just make yourself start going again, and dont think about it. Just get up and go. Your allowed a few days off - Chin up
But i would suggest finding an outdoor training group - I go 5 times a week and love it! Mainly because of all the girls i do it with - but also because its great motivation. Even if i dont want to go - i turn up see there smiling faces and im ready to work out... Motivating yourself is hard - so find a group to motivate you.