Sciatica/Back Pain?

Madison
So I have felt sciatica pain on and off throughout my pregnancy. I'm almost 20 weeks now, and it seems to be getting worse (understandably). Today, after taking my daughter and dog on a walk over to the dog park, I can hardly walk, and bending over is out of the question. 
Any advice on how to treat it? I use heat treatment, and that seems to be the most helpful, in the moment. But as soon as I get up/turn off the heating pad, it comes right back. I really am trying to stay away from meds (though I do take Tylenol sometimes, but it never seems to make a difference), just because I don't like taking too much in pregnancy. Thanks in advance. :( It's hard having debilitating back pain with a toddler who is steadily growing more clingy. (She's 27 pounds, and a couple weeks ago, I had pulled some muscles in my ribs from lifting her too much).