We've all made mistakes in what we say to our spouses at some time or other. I agree that if you've apologized verbally, you need to drop it; quit bringing it up. But if things are still weird, write a letter not necessarily about that specific apology, but just writing to tell him how important he is, and how you know that all the work he's doing now is done out of love (because he's working/studying for a better future), and that you appreciate him. As a wedding gift from one of my oldest friends, she gave us a book called "The Five Love Languages" which explains how couples can get tripped up if they feel like they're being ignored or something, when in actuality each person is trying to express love....but in the way they personally feel loved. For example, some people shower with love because that's what they themselves want, but that might leave someone else feeling smothered because the way they express love is to "do" things like work hard to provide for the family, or fix things around the house. It was a great book, and really helped our marriage.
One thing I did that rocked my husband's world was this: I made a list (which took days!) of EVERYTHING I could think of that I loved about him, or was thankful for from or about him, etc....I proofread it to make sure there weren't duplicates. I got ideas from other friends because sometimes you overlook things that are special but you take for granted. I took some different colored construction paper and cut our little rectangles and wrote out my list on these scraps. Then I rolled them (lengthwise) with a pencil and slipped 1 each into the balloons. I went to his work and blew up the balloons (don't drink while doing this, LOL) and stuffed his car with them. Do you know how many balloons it takes to fill up an Isuzu Trooper??? I filled his car up, and walked into his work with a card about being thankful and how I loved him for everything he puts into our relationship. I taped a giant knitting needle into the card and wrote "ps-take this needle and a bag with you to see SOME of the reasons why I love you". When I saw him at work, I said I was in the area and just wanted to say hello and gave him the card with instructions to open it later, but before he left to go home.
I went home and cooked a special dinner (not hard, just special) and waited on the couch for him. That was 3 years ago and I can still remember the smile on his face when he came home. With each balloon that he popped with the needle, out came a "reason" why I loved him. (You should have the kids help you! We didn't have our son at the time, but that way he's got the parental thing covered too). He popped as many as he needed, to be able to drive home safely, and then had me come outside and toss the hard to reach balloons to him so he could keep doing it. He said noone had ever done anything like that for him before, and he also got an ego boost from all the comments he got from his coworkers that saw it in the parking lot. Stuff like "Wow, that's love" or "You must be something at home that we're not seeing" or little jokes like that. He kept those reasons in a bag until I found a little treasure box in the craft dept of Walmart. I strongly suggest reading that book so you can understand, even when frustrated, where he's coming from and that will help you feel better. And as for the balloon thing, I suggest you do it when it's not "death hot" because otherwise it might take out some of the joy to stand in a baking hot parking lot for an extra half hour popping balloons, lol.....I had done mine in November for Thanksgiving.