My son is not HUGE (only 20 lbs), but I am pretty small and am having a VERY hard time carying him anymore. I have two front carriers - Evenflo and Infantino, but never liked those much. I also have two slings that were originally Didymos but were converted to Hotslings (bought off ebay). I can't wear him in any of these for more than just a few minuts without being in a TON of pain. My back and shoulders are throbbing from the weight almost immediately, and after about 15 or 20 minuts of this, my head even starts hurting. This is a huge problem when we're at home especially and he wants to be held, because I have to put him in a playpen at some point or I can't get anything done. Any advice, or will I just never be able to wear him anymore? I'm on a very tight budget, so purchasing a new sling is out of the option.