Martial Arts is great!!!
I found it about 4 years ago - to me it isn't boring like going to the gym. Always learning.
I'm about to go for my black belt in Isshinryu Karate. Been working at it 3 years. I started losing weight so I wouldn't be huffing and puffing so much. I think I'll lose about 15 more pounds - the test is scheduled for the first week in February.
I also take TaiChi - been taking that about 4 years. It has done wonders for my bad knees and got me moving so well I started the karate after about a year.
Don't give up -- It's all about practice and moving and becoming that badass you always wanted to be