Missing deadlines/tasks due to workload

[u/Good_Skirt2459]

My workload is high and I work about 8 hours through every day but there are some things which drag on. Work is constantly coming in and it's variable so I've just stopped giving estimates. I would think something should take a week, so I'd say 2 weeks, then I'll get an email about some urgent project that winds up eating 1.5 of those weeks.

How can I push back or explain it while maintaining professionalism? I've had projects where I've pushed the deadline back 2-3 times because other immediate things have come up.

We're a 4 person IT team, I'm the sole "developer" here, and maintain lots of legacy code and apps for the business. Many of these are critical to the business, so if 10 people can't work because they can't use the system they need, it's not something I can ignore.

Advice? I don't mind the pressure but I'm mostly concerned about gaining a reputation of being unreliable.