Issues with giving & receiving

I’ve made a few posts on this subreddit over the past few months, and after 21 years of no relationship and/or sex, I have finally been dating someone for the past two or so months, so yeah, really early days. Against all better judgement I’ve fallen into the coworkers to friends to lovers pipeline.. I’ve known her almost three years and only in the last year really developed strong romantic feelings for her. Anyways that’s irrelevant, long story short is we are in a relationship now and it’s going great. Wlw also.

I spend all my time with her, and I want to be around her all the time. It’s very strange to feel like this because I’ve had such a lack of anything for my entire life. I have always been independent and sure of myself, and also sure that I would never become the lovey dovey type because that simply ‘wasn’t for me.’ I have spent my whole life so sure that I would never have sex because I never felt like it, until now.

I just am struggling a little bit with my sex drive, and this could be because I had never done anything sexual with anyone prior to this, but I find myself getting horny when we makeout (as one does) but I get exhausted VERY quickly when either she goes down on me, or vice versa. It’s especially apparent though when I’m giving.

She loves giving, and I love that she loves that, but I don’t think I like giving as much as her, but I HATE feeling like that, because I don’t want her to think it’s anything to do with her or a lack of attraction etc. I’ve briefly explained demisexuality to her but not in great detail. Though from my understanding, sex drive (when bonded) doesn’t necessarily have much to do with demisexuality itself, does it? It’s nice to be wanted, and to finish, and to make her finish — but I communicated to my girlfriend that I think I could probably go a long time without sex and be fine. Am I overthinking all of this? I just really really don’t want her to feel insecure or like I am ‘disgusted’ by her or anything by not wanting to receive and give constantly. She has made me finish far more than I have to her, and it makes me feel like a bad partner, like I’m not pulling my weight. It’s important to note also that she has NEVER said that she thinks that and never makes me feel bad about it, but I still do.

Any advice would be appreciated.