Depression Support Group
Depression is a real and debilitating condition that is often misunderstood by family and friends. Its meaning can range from a prolonged period of sadness to an actual mental illness with specific symptoms. Find and share experiences with others who are going through the same struggles.
I would just let your girls ruin their lives if that's what they wanna do. They will come running back begging forgiveness eventually.
When I was their age I didn't like boys, was not interested in dating, because I knew it would take all my time and blow any chances of me getting thru college. So I waited until I was 24 and graduated to start dating. Most people think there is something wrong with me for doing that.
If your daughters would rather succumb to social pressure and be having sex at their age and not thinking about their futures then that is what they will do. They likely think you are a good mom and saw that you raised them just fine, so maybe they aren't afraid to follow in your footsteps.
I would make sure they know they need a job and good insurance to get annual exams so their doc will prescribe them birth control. Also Walmart has generic birth control cheap, you just need a prescription.
Make them get the hpv vaccine. Trust me I didn't get it and have hpv now so you want to protect them from as many stds as you can. Also many college students are at risk for meningitis so get that vaccine as well. Just do the best you can to protect them without being overly controlling and trust you have raised them well enough to make good choices. If they get pregnant and come crawling to you to raise their children, I would say no, go get a job and take responsibility for making the wrong choices.
Best of luck.