I need some advice

I've been with my boyfriend for about a year and 10 months now, we have always been really close right from the start and then things started getting more serious and we became intimate. We waited about 3 months before having sex which for some people isn't long but it felt right at the time, we used to do things alot and kissing was always a big part of our relationship. But for the past like 4-5 months my boyfriend doesn't really kiss me anymore unless I kiss him, I ask him why and he says it's because relationships slow down the longer you've been together and I get that. I just feel guilty when I kiss him because he always seems like he's more interested in watching what's on the tv? At the beginning of our relationship I was always too shy to give him a blowjob but would give him a hand job whereas he was always confident when it came to doing things to Me (we was eachothers first time for everything). And now I am obviously alot more confident but we don't really have sex or anything anymore, only on the odd occasion. I try and start things and I understand if he doesnt want to do things but he always asks me to stop and obviously I do because I respect him but I don't understand why he does it? Am I doing something wrong? Should I be worried?