I found the first trimester incredibly challenging as my MS started at 6wks and DD was only 20mths (from memory?) and very active so yeah I was really, really sick and tired alot of the time!! That was so hard vomiting every day and looking after her when all I wanted to do was stay in bed most days.... I had some good days though but most days I felt pretty rotten..... hardly could eat...let alone make her food to eat!! But we got there and you just do it because you have to and you don't really have a choice!! I would put on ABC2 for her more often than I normally would and so she got to watch lots of playschool etc while I lay on the couch resting and talking to her.
You can still interact with your child without having to sit on the floor with them and be really active etc..... I'd get her to bring puzzles over to the couch and we'd read ALOT!!! Lots of books.... in bed too!!

It gets easier, especially when your MS goes, you can be yourself again, but then I found it's hard now that I'm heavily pregnant from say 33 weeks it's become very tiring for me...... but I'm HUGE this time around too which isn't helping!!! My tummy is massive LOL.....

You'll get there One day at a time.