Any sahm with a child in preschool/childcare? I need reassurance

I'm a sahm of 3 kids, with my husband we agreed to look for a preschool for our oldest to start at the end of the summer, he'll be 4 in July so perfect timing. But I feel guilty because our plan until recently was that the kids would stay with me until they start kindergarten. But the truth is that I'm struggling to take care of them, homework etc and we're a bilingual family and because of this, hedhas a speech delay in English (not really a speech delay but we don't use English except if we're not alone so it's not as natural for him if that makes sense). So we believe preschool/pre kindergarten would be great for him but I can't help but feel guilty and sad, I feel like I failed as a mom /sahm not being able to give him the attention and stimulation he needs.