Please help.

My husband and I got our bro in 2017 we ended up finding out I had an empty sac so of course had to get a dnc to get it removed. We then tried and tried and nothing so I them ended up getting surgery to remove scarring on my uterus and tubes November 30 2018. Then about 3-4 weeks ago we finally got another bfp we where so happy and then this past Saturday I ended up miscarrying :( I am so destroyed and sad and just confused. But my question is how long after is okaii to start having sex again I am scared of infection also how fast after did you amazing women end up getting pregnant again and did your pregnancy after your miscarriage last did you have your baby? I do have 2 children and my youngest I did have a misscarage a few months before but this is 2 misscarages in 2 years. My children are not my husbands bio kids he dosnt have any but he loves my boys like his own♡ I just wanna give him another baby and finally give him his very own bio child. I just feel so heart broken and lost I keep feeling like I failed my husband. Sorry for this post being so long I just feeling lost