7 month old. FTM Help?!

So, my little one just turned 7 months, it’s been getting a little difficult. I’m a first time mom.

1.) Whenever I leave her sight, she starts crying but then they turn into cry-screams. (Screaming at the end) I tend to come back to her within the 10 seconds. & she seems to calm down.

2.) While in the car, she cries if there is no one back there with her (usually I’m in the back and dada drives, but sometimes I go out with her)

3. Don’t even get me started on the crib. I’m able to sit her inside her crib while I’m in the same room cleaning and entertaining her. But when it comes to sleepy time (Bed time or naps) she will scream!!! I usually let her cry it out but it can go up to 45minutes. She immediately stops when I carry her. I try to comfort her while she’s inside the crib before picking her up, but she just cry screams louder.

4. It seems as if she’s more attached to me than to dada. I’ve been with her since she’s been born, but I’m planning on going back to work.

In conclusion, I feel like she’s hit the point where it may be separation anxiety. I’ll talk to the doc about it when I can, but In the mean time. What can I do? How can I let her know that I’m with her and such.... Thanks guys.