Yes, ejaculation and orgasm are two separate processes. Just as it is possible for men to orgasm without ejaculation (it happens occasionally to me, but it's not something I can control) it is possible to ejaculate without orgasm.
It used to happen occasionally to me, but since I learned the signs - not being into whatever was happening, so barely having an erection etc - I now just stop doing whatever because I know the end result won't be with the effort.
Do you still enjoy the arousal and plateau phases of your sexual response?
Orgasm intensity can change over time, and it's likely that they will get better even if you don't do anything about it, but have you considered talking to your GP / a sexual health clinic? They can investigate any possible causes.