I feel your pain. My wife and I bought a sailing dinghy, seldom found time to use it, and found it stressful every time we did, then we lost a few hundred when we sold it.
Maybe you're not using this boat right. Seriously, when I used to use my boat a lot on my own, I found getting a 3 hp "egg whisk" instead of using the heavy 9.9 wth a separate tank made every trip easier.
Do you need the engine you have with a slatted floor? Boats with slatted floors tend to caterpillar across the water anyway. Two thoughts: get the smallest lightest engine that will push the boat, or get a faster more exciting boat. Personally, I tend to go for small and light.
You commented on the padded seats. Most people sit on the tubes rather than the seats.
My 10 with plywood floors and a 9.9 goes from car to water in about 30 minutes and from water to car in slightly less. The more times you do it without any pressure on yourself, the quicker and easier it gets. Have you practised on the back lawn?
The electric pump should take some of the grind out of assembling the boat, but probably doesn't save much time.
Look for places to launch. Try Boatlaunch.co.uk Home Page
and search. Look for inland marinas, winding stretches of river, canals, waterside pubs. Combine the boating with a picnic or a stop at a pub or café. A destination or a natural half way point makes every trip better.
Do you have an anchor? Some of my happiest memories of boating are riding at anchor in a quiet backwater, reading, eating a picnic, or even having a swim. Make the boat part of the day's activity, rather than an end in itself, because, to be honest, chugging along in a boat for hours on end can be tiring and dull.
Do you own a canoe or kayak? A small inflatable will tow one of these, giving you more options for things to do during the day. You can even buy good quality inflatable kayaks and canoes easily for a couple of hundred quid.
Learn some proper knots and take a pride in knowing how to anchor or moor the boat and how to secure items on board "the proper sailor's way". Give the boat a name, and get a flag - treat it as a real vessel, not just a thing.
Most of all, it's meant to be fun, not a drudge.