Jenarry - please don't beat yourself up about this. I've been where you are, and it's a sad time - but in the great majority of miscarriages, the mother has done nothing at all to bring it about. There may have been something the matter with the baby, or a hiccup with the placenta, or anything - it's a perfectly natural process that some babies don't go to term. Mourn your little one, but on the other hand, look on it as evidence that you can conceive, it's a positive in a strange way, and that's the way I looked at it - to have conceived after several years of trying. You can do it, you'll do it again when you're ready. Your grieving is natural, and although you won't forget, you and your husband will be OK - it must be hard for him too.
Regarding your colleague - she's going to feel uncomfortable. My SIL and my friend were both pregnant at the time I miscarried and they felt awful that their babies were OK. You will be fine, though - and we are here if you need to talk.
Jenarry, please don't also let this sad event influence your thoughts about the troubles you have elsewhere in your family, don't feel that you now can help out in that direction just because you might now have "capacity" - your little family can and will get through this. The stress of all the other things going on can't have helped your frame of mind in recent weeks.
I wish you well, please keep talking to us if you feel the need :-)