He sounds like my ex-husband.I don't see what not being in a relationship has to do with anything. If you haven't been sexually stimulated in awhile, your libido can actually decrease which is why I hate cum restriction. However, if you've been regularly stimulated via a vibrator, it could be that your clitoris is a bit desensitized. If vibrator use isn't the culprit, it could be that he just hasn't found out what works for you. As far as his age, I generally find that older men have more experience in knowing how to bring a woman to orgasm, but this IS a generalization since my ex-husband is 11 years older and still an idiot! Anxiety can also cause difficulty in achieving orgasm.
As far as this being normal, I don't know since I don't know what's normal for you. It's very normal for me to have a difficult time cumming with a partner. If I'm focused on pleasing him, I can't focus on having an orgasm. If he doesn't stimulate my clitoris at all or correctly, I can't have an orgasm. He may be too rough with it or not touching the right place. I have had to move his fingers around and tell him what feels good. Usually, though, once he gets me going, I can have multiple orgasms....it just takes me awhile to get there. I warn my partners that it's hard to get me off, and if they act like it's too much work....I find someone who wants the job.