Hi Rocket,
I've been in a long-distance relationship for going on 5 years. It's super long-distance - we live on opposite sides of the Atlantic, and visa options are somewhat grim. Pretty much every relationship I've been in has had at least 2 hours of travel time difference. So, yes, you could say I'm fairly familiar with LDRs.

Haha.
Incoming wall of text.
I've definitely found that the phone helps too, as texts can get convoluted. Video can be even better if it's possible.
The other thing that we've found can help if things are seriously messy is to stop, spend the night apart and write a letter to each other. In the morning, we send our letters to each other at the same time. This can help when neither person is feeling heard, because it gives you each the space to express yourselves without the restriction of a small text box and without the other interrupting or invalidating.
Other things that we've found immensely helpful for LDR communication include:
- Don't get into difficult topics if either of you are tired, hungry or overly-emotional. It's such a simple thing, but can often be overlooked, especially when you can't physically see what's going on in each other's world. If you're in the middle of a tricky conversation and it's heading south and one of you needs to sleep, eat or do something important, honour it. Working on this has saved so many upsets between my partner and I!!
- Agree that either of you can call a timeout at any point if things are getting sticky or you can't think straight.
- If you do take a breather, try to make it 30 minutes. I've read various studies that say that we tend to feel calm after 15 but our body does not settle until around the 30-minute mark. I've found this to work well.
- Never leave each other hanging. It's so important in an LDR not to just hang up or end the conversation mid-way without letting each other know when you'll be back. Give a time frame.
- Learn to be less reactive. This has been a huge one for me. I'm slower to anger than my partner, but I realised that I could still be very reactive. I'd be very quick to feel scared, defensive, anxious, etc. in the face of conflict. I learnt that even though I might not have been the one shouting most of the time, I still wasn't helping because I wasn't able to listen with a clear head.
- Continue to educate yourself on communication, no matter how much you already know! Books like Non-Violent Communication and The High Conflict Couple are brilliant. I've also found books designed for BPD relationships to be extremely useful, even if you're not dealing with a borderline partner, because borderline interactions often require the person on the receiving end to be very conscious of validation, patience, good boundaries, etc.
- Active listening all the way. When things are getting messy, stop and revisit when you're both feeling calmer. One of you then has to be the bigger person and let the other go first. If you're the one always letting him go first, so be it. This is one time that text (or preferably typing on a laptop) can be helpful. Let him know that you are listening, express patience. Really listen. Don't interrupt him. Wait until he's finished and give him time. Mirror back to him what you understand. Show him that you hear him. Empathise and validate as much as you can. Own what you can own. Then switch.
I used to be very much this way, as my relationship with my partner was also extremely intense during the first couple of years. However, such intensity (as you probably know) isn't always healthy or helpful.
What helped me here was to learn more about emotional regulation. If you're feeling so bad after an argument that you can't function (spending all day in bed, not eating properly, spending all day crying, not being able to focus, being a general mess

), this might be something you can benefit from. The calmer you can train yourself to be in the face of conflict and difficulty, the easier things will become. That starts within you and it's something you can start doing straight away. it's something that will improve the situation even if your boyfriend changes nothing on his end!
My final piece of advice...
Try not to look at distance as the enemy! If you look at it as a situation you share, you're more likely to remain bonded and avoid distance-related conflict. If you look at it as this awful thing that needs to be eradicated as soon as possible and you're just scraping through until he can move in, it's going to cause more issues. Have fun with the distance. Send each other physical postcards. Have a Skype and wine night once a week. Send each other articles and videos and songs. Go into Utherverse or Second Life and play around with virtual presence. Start a private Pinterest board with ideas for dates or trips or things to buy for when you live together. Do things that embrace the relationship rather than getting down about the distance.
Good luck!