Get used to it! Sorry that sounded harsh. My dd has been in nursery since she was 10 months, five days a week m, I work full time.
I feel so guilty, so so so guilty every day, and every evening, I spend probably around an hour and a half with her all day in the week
(single parent, no choice but to send her, no family etc). Everyone on my case, 'oh you'll never get this time back, they grow so quickly' etc etc etc.
Then at weekends I feel guilty as I have to drag her around doing chores like shopping and life admin that I don't get the chance to do in the week...
But.. she absolutely loves it! She has made lots of little friends, she is so well cared for, and I console myself with that fact. She does activities there that I wouldn't have time to do with her (yes, I know, terrible mother), it's been brilliant for her social skills and confidence.
Could you book into a class or something on the days you have off, so you can do something meaningful/bonding together? We do swimming lessons at the weekend which she loves, and that's 'our thing'.
Also, when I pick her up at the end of each day, she comes crawling over, huge smile on her face, so that's the best part of my day. Although then I feel guilty that she's missed me.
Long story short, you are human, you love your baby, you will feel guilty (my mother likes to remind me that this is merely another part of being a parent). But hopefully your ds will settle in quickly and have a ball!