This has happened to me before as well. Usually I am ready to go, pistols drawn, all hot and either my willy doesnt want to get it done, or it takes me a year to orgasm. Honestly, the best advice I can give is by saying it is all in your head. Before using viagra, and cleary you CAN get hard so I would not suggest using it, try a different route. Viagra/Cialis can become somewhat of a crutch if used too early--you may not want to give it up when you start, or worse may not be able to perform without it.
A big problem I see comes from everyone on the boards talking about inability to perform in bed. Of course, there is no harm in talking about it because it is a natural and many times unavoidable effect from using AAS. But people ted to Pysch themselves out, especially younger guys who should have no trouble getting busy between the sheets(or the hood of your car, public place, etc). Compared to other cultures, not only do we have less sex, but our stamina and ability is down-right pathetic.
For instance, there are tribes in other cultures who fuck all day long. And I am not kidding. 60 plus year old guys are waking up, fucking the wife, going fishing, fucking the neighbors wife, coming home, and fucking the wife again and maybe having a little night cap with whoever is available. This behavior is normal for them. I know there are other variables to consider, like stress, hours worked, quality of life, etc, but having sex four times a day is still having sex four times a day.
Okay...back on track. My point is that physically it is probably possible for you to have enjoyable sex, but your brain may be holding you back. Next time you and your wife are going to have sex, focus on the act. Focus on the pleasure. Think of her, her breathing, the feel of your skin against yours, the scent of her body, the sensation you both feel sliding your penis inside her, the raise in body temp and slight lightheaded feeling, etc etc etc. The moment you think "oh shit, I hope I can get the job done tonight" you have already defeated yourself and taken about all the pleasure away and the reason you were going to have sex in the first place.
And take your time. Don't make it a race to see who comes first. I don't care if you fuck, screw, make love, have sex or whatever you want to call it, don't focus on the climax and what you have to do get there. It is just going to bring about unwanted anxiety and hinder your ability to reach orgasm, or make it impossible. Make the act a journey, one where you want to stop and explore every portion with wide eyes and open arms.
My goal here is not to make this sound like a 2nd rate romance novel. I want you to get your head in the game. Are you a sports fan? You know that success is 90 percent mental, right? Same thing in sex. Don't defeat yourself before the game begins. It is YOUR body and YOU can make this happen. Trust me. You just might be surprised on what you can accomplish.
And tell me how things work out.