Ive been dating my boyfriend for almost a year and he makes me so happy. On the other hand there is this guy that I used to date that I think I might still love. Is it wrong to think about him in a way like that? I don't want this to mean I'm treating my boyfriend wrong.

As long as your devotion is to your boyfriend and you do not consider cheating.
It is rather normal to still have a place in your heart for an ex.

As long as you wont cross the line of being an ex now "good friend, thats fine.

I would try and keep my distance from the ex... you have to keep reminding yourself that they're an ex for a reason. You have another boyfriend now, so your heart should be focused on him and not the past. I know that you'll always still care for your ex, but it should be an entirely different type of 'caring'.

Remembering old loves is perfectly fine. Don't fret those memories or those lingering feelings. Also, don't romanticize them. Your current relationship should not be endangered by old ones. It's totally uncalled for.

You will have ups and downs in every relationship. All of your relationships will come to an end, except for the last one. You probably can't say for sure this current one is going to be "the last one", can you? So, it's more important than ever that you give it it's proper chance.

If your relationship is going to end, and most do for one reason or another, it needs to be for reasons of long-term incompatibility between you two that are real, not because you're fantasizing about old boyfriends.

Keep your focus. Enjoy the fond memories and all, but keep your real-life in focus.

I'm married, but remember most of my exes with some fondness, so its normal, but we forget sometimes that those exes, for what ever reason didn't work, so why go back, or dwell over the past too much, when you have happiness now?