So I'm on summer holiday for the next 2-3 months and have been in this relationship on off for 6 months. We're going to do a long distance relationship within that time.
I would like to know what to do to keep it going?

I've looked around and i've found talk everyday, have long distance date nights and work out to keep that "value" up and letters and romantic things

what i'd particularly like to know is what the hell do u talk about?
Emotions, your day, news?

and of course how to keep it going?

I will see her after a week or so for 4-5 days, maybe meet the rest of her family. But after that we will be apart for 1 & 1/2 months.

Show her you appreciate her.

Show her you care.

Avoid mundane stuff if you can, for the more mundane stuff, less is more. Be interesting, tell her what is exciting, and always say that you look forward to seeing her again.

We're finding it hard, we literally go on SPAM have the shittest conversations get bored and go off, she's told me she's worried and doesnt like being the SPAM girlfriend i said i'd be over to hers soon.

This is annoying me and i cant seem to relax

Talking on the phone every day can get tedious.

Even your best friend, who you talk to most openly about everything, would get bored with you if you spoke every day over the phone.

Also, there's not a lot of new things that happen to you day after day. Most everything is a slow process that just slowly changes every now and then.

If you guys have been on and off before, why don't you set things aside again until she's back?

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"Let me ask you something. If the rule you followed brought you to this, of what use was the rule?"

Agree with the above, phone calls/SPAM get tedious..think of ways to make it fun! Watch shows together, gives a connection without having to be with one another.

so shit just went down, we had an argument where firstly stated that a friend thinks she should go single then she said she's also thinking about it.

She says this because we have not got much to talk about anymore (over SPAM only in my eyes). after i told her it was her choice if it's not working then to end it. i was a little apologetic i stated how the reason i dont have much to talk about is ive not been doing much and i want to tell her about new things going on in my life, i told i was not comfortable with ldr and it is making me nervous when getting onto SPAM (feel forced to be energetic and happy on SPAM). she then told me that i dint care and i had a smug look on my face as i said my points and then hung up on me after i said if i dont care then why am i explaining to u why im acting like this obviously i dont want to lose u but if it's got to happen it's fine.