Anyone have any good advice on how to actually gain weight?

I plan on making a doctors appointment but they are booked the hell out. I’m so desperate to gain weight. I drink ensures every day and try to eat as much as I can. But I’n at a resting weight of 87 lbs and I’m so insecure. I had a baby a year ago and I never felt better/more confident/healthier than when I was around 110-115. I looked amazing and I breastfed so I dropped that weight so fast. I feel sickly and unhealthy every day. No clothes fit me so I’ve resorted to wearing all of my husbands baggy clothes so no one can see my body. I’m so desperate to gain weight I just want to know what to do. If anyone has any real advice about gaining just a bit back please let me know, it would be super helpful.