Mixed Emotions

I lost my sweet baby boy Hendrix in June of this year. He was 20 months old. I have been beside myself with grief.... he took such a big piece of me with him when he died. My two remaining children 12 & 10 lost their brother and their mother that day. I will absolutely never be the same. I am a shell of a shell of who I once was. My SO wants to have another baby. I am 34 and will be 35 in December so I know my best fertile years are almost behind me. We each have two children from our previous marriages. Hendrix was our son together and he tied our family together so perfectly. I was going to wait a year and see how I felt but my mirena IUD came out on its own in the beginning of September. In my grief groups, those who have had children after losing one have said that they've never regretted having more children but feel like they would have regretted it if they didn't. I'm just so lost without my baby. It's been 4 months since I've heard his sweet little voice call me Mama or felt his amazing hugs or snuggled him at night 💔 I feel like I am betraying the memory of my son by even considering this. I agreed to not have my IUD reinserted for a month and see what happens. I am also going back to work and am stressing about a position that I really want. I was a stay at home Mom the last two and a half years and I'm so thankful now that I was because I never spent more than 9 hours away from my boy for his whole life. Everything is dark and different and lesser. I have no idea what I'm doing. Has anybody been through this? How did you rationalize having another child?