New to My fitness pal

Hello,
New to my fitness pal. found the site on my market android and so far loving it. I am a 43 year old mother of 4, ages 23, 22, 16 and 3 yrs old. I have been battling weight loss for 22 yrs. now since after giving birth to my oldest child. I have been on a yo-yo diet. I lose, gain, lose, gain. Last weight loss was 30lbs in May 2010 and since then have gained it back. I know it's unhealthy and would like to finally try and lose the weight permanently. I do have my 3 yrs old to think of as well as my 16 yr old who is disabled. So hopefully this site will help me with this battle once and for all.