Please help, boyfriend problems. I need advice. ASAP?

Me and my boyfriend have been dating a little over a 3 years, tomorrow will be our 3 year 2 month anniversary. He recently got another job so now he works during the week and weekend, and going to school.(this means we cant see each other or talk to each other often) we haven't talked in 3 days expect the occasional "i love you" text he'll send me. But I noticed even on his days off he is still too busy for me, and says he wants "alone time"

I assumed he was cheating on me when he wouldn't kiss me or hold me in front of his work. He tells me he's not cheating but ever since then he has been acting weird. When i came over to his house and we were going on a walk i tried to kiss him and he said that he didn't wanna kiss me it made me feel disgusted with myself.

I will admit i can be a little clingy. i was just wondering if all couple go through this "no talking stage"
we are engaged and i'm moving in with him the summer..maybe he's scared or getting cold feet? should i give him his space? im just so confused..