Why did I move on so fast from a relationship that was my whole life and I was so attached, I moved on by 2 months?

I’ve made the rebound relationship mistake in the past. To prevent myself from doing it again, I made a rule to casually date a person for at least a couple of months before getting intimately serious with them. I know that might seem to be moving very slowly given modern life but I wanted to ensure I was past any infatuation for them before considering commitment. Refraining from complications brought on by intimacy early on makes life a hell of a lot easier to handle emotionally. Especially when you have that itching feeling that you should not feel so comfortable with someone new just yet. Give your mind and heart a chance to catch up with your groin so your decisions will be in alignment will all aspects of your desires.

Be honest with yourself. Were you afraid of being alone or really missed having someone around? Were you looking to replace what you lost by having a partner? Were you so sick of your ex that the first person you met seemed absolutely excellent “by comparison?” Did you fall out of love a long time ago and the break up was well overdue? It is important to come to terms with what motivated you so that you can address that issue and be a healthy partner for this new person.

A lot of people jump into rebound relationships to fill some need or void without actually taking the time to see if they are genuinely attracted to the person. Not just sex appeal. Not just an appreciation for paying attention to you and giving you some validation. Actually loving and caring about this person and wanting to build a relationship and life with them. Make sure you are actually wanting this new commitment you’ve placed yourself into quite rapidly after a relationship you say meant a lot to you.

Do Marines really not need sleep during combat training or in general? If this is true, how and why is this possible?

Unfortunately, only you can answer that question. I recommend you take some time to consider your emotional state right now. You may seem fine but if you are questioning your actions, you are acting against your own better judgement. So I highly recommend you slow things down in your current relationship before things get too complicated so you can think about what might have lead you to do this and ensure your heart is in the right place before you move any more forward.