[@ThatLostDude] The best antidote to 1x1 rejection woes is to join a group RP. Generally speaking, GMs are happy to take on several players and aren't going to be nearly as fussy as people in the 1x1 section. Best part is group RPs can survive if a few people flake off. Even the shortest lived RPs usually last a few months, so you can get some posting in even if you have an inexperienced GM. Though if you do your research you can pick a GM that knows what they're doing. 

The second thing to realize is, as you mentioned, you might be the problem. Unfortunately you aren't going to get much feedback from 1x1 partners. A lot of people have "retaliation anxiety" and would rather just stop talking to you altogether than work through your problems. So you to look back through and really consider why you think this person stopped writing with you.

The third thing to realize is it could be them. Maybe they didn't have as much time to dedicate to an RP as they thought, maybe the idea wasn't as fun as they thought, or maybe they just can't stick with anything. 

Fourthly... Aren't you being a little impatient? I don't know how long "a few days" is, but most people can't do daily posts, even if they say they can. 

Just about every group RP I've decided to GM in recent memory has successfully come to an end. It might have taken a few years or as many as five, but it happened. Out of the several 1x1 RPs I've tried to get going, few of them start, and almost none of them made it past the first page. If rejection is an issue for you I would stay away from the 1x1 section.