Your daughter's language will come on, she's not yet 2. I used to worry about my DD's speech, but I needn't have. Try not to put yourself, and your kids, under too much pressure. Before you know it, they will be grown up. Try and enjoy the good stuff, really focus on it.
You ask for advice, I'd say limit iPad time and plug into them when you have their attention. I'm not saying don't have screen time, but when they don't have it, be really present with them. My kids grew up in an age before iPads, I'd have absolutely used them too, before I get bashed.
Also, as a parent, some days are better than others, if you have a bad day, it doesn't mean tomorrow will be.
Also, 2 kids under 2 is exhausting. Be kind to yourself op. Accept that you are doing your best and that is enough. With social media, there is this artificial presentation of the "perfect" family. These people show you what they want you to see, not the reality of life. It puts mums under so much pressure. Again, I'm glad this wasn't around when my kids were small. Even Facebook, people don't show you the shitty side of life, the struggles.
I wish I could go back and have my kids small again, it really does go so fast. If I could tell myself one thing as a young mum, it would be to let them be more independent. I jumped in too fast to help them, instead of letting them figure it out themselves. Helping them, isn't helping them, sometimes.
Good luck op. As long as they're happy, loved, safe, fed and warm - they'll be absolutely fine.