Any working mums who don't get enough sleep

I have an 8 month old son and I will be going back to work in three weeks.

I work with young children and will be doing three half days from 8-1 and two full days from 8-6.

I'm so worried I'm gonna be drained and tired. My lo use to sleep during the night from the age of three months but in July he suddenly changed. He will just wake up all the time throughout the night. Sometimes he does it because the dummy has fallen out so I'm up about 5-8 times to put it back in. Other times he just wakes up chatting to himself or cries so then I'm up again. He has a good routine of bath time, bottle and in bed by 8pm. He sleeps fine but once I go up to bed it's like he knows I'm there and it all begins.

I'm gonna be having to get up early to get myself ready and him and drop him to his childminder and get myself to work.

I'm just worried that he is getting lack of sleep and so will I and that I'm gonna be so tired while at work. Anyone else been in the same situation or are?