Putting on weight while strength training :.0

This month has been great for me with consistent workouts with lots of strength training. I was sad to see I keep putting on weight on the scale! I'm sure it's a combination of things, including being careless with my portion sizes. I'm 50 and don't want to succumb to the "It's all down hill after 50". I have exercised and watched my diet my whole life; strayed into some unhealthy extremes in my lates teens and twenties. Some days all the education is overwhelming: wash your produce, eat grass fed meats, don't eat packaged foods, eat 6 small meals a day, drink lots of water, avoid caffeine. Yikes! It's our own responsibility to take care of our bodies and sometimes I just want to whine. Ha! Any other 50-something YO women out there in my shoes?