I write my strip every morning. I used to have a backlog but I used it up. I like the challenge of MAKING myself come up with a gag. It's hard and sometimes I'm under a lot of pressure but I force myself. I usually write and draw the strip in an hour so it doesn't take much time out of my day but I force myself to do it. I don't believe in writer's block.
I have written for comics and for television so when someone says, 'I want something funny', I make myself write it. Keep the characters down to just a few and establish their idiosyncrasies. Play on them and let your mind wander as to what might happen. It works for me.
I haven't done webcomics for years but I do enjoy doing them. I am currently doing a daily strip and a weekly comic page. It's fun. I don't want any more than for people to be reading them. I don't see pots of money at the end of this and it's not an ego boost. It's just fun.
I want to tell stories and gags and that's all there is to it. Don't look too deeply just enjoy the fact that you are reaching an audience and hopefully that audience goes away happier for the experience.
In my opinion this is NOT the way to become a professional comic artist. If the big boys turned down your stuff when you sent it to them they probably had a reason so just enjoy the ride.
I have worked with Diamond and I have to tell you that they demand a lot. They want to make sure that they have continuity before they will represent your work. On that basis you have to be able to prove to them that you have either the series printed, That you have the material for the series in place and that you will not let them down in any regard.
Because they are the ONLY major distributor of comics they take a hefty amount of commission. Be aware of this if you are getting your budgets together to start printing.
Finally, there are no guarantees of sales. Diamond will show your comics to comic shop owners via an order magazine. The comic shop owners have to want to order your comic. They have very limited shelf space and NEED everything they stock to sell.
It's a tough call. I would never want to put anyone off but don't imagine self publishing and going through Diamond is a sure fire way to success. It isn't. In the same breath, if you have a good story, great artwork and the money to waste if nobody buys your comic then go for it. It's a good feeling to see your comic on the shelf in a good comic store.