You really can make reaching your goal painless! It is a matter of forming a habit. Intermittent bursts of effort are generally much less effective than constant small steps toward your goal. You just need to get a habit going.
Tiny changes can lead to big results. You may not notice the change in your daily life, but the results will show in time. For instance, the typical adult puts on 1 to 2 lbs of weight per year from young to middle age. To send this trend in the opposite direction, and be losing that amount, you would just need to give up 30 calories per day. That's about ¼ of a can of coke, or seven M&Ms, or a shot glass of wine, or a third of a banana. Alternatively, go for a 600 step walk which is about ⅓ of a mile. Just do the right things on the right trajectory without thinking about immediate change and the desired outcomes will arrive.
It is likely you want results faster than over several years but once you have got a habit going it is much easier to build on it. A habit can take anywhere from 18 days to 254 days to form. It depends on the behavior, the person, and the circumstances. Starting easy is the key. Maybe getting dressed to go to the gym is the place to start. Then dressing and driving to the gym. Then going in and mainly hanging out. And so on. Really, whatever it takes to build momentum without stressing you out.
Without desire to do something you just can't do it. Mice were deprived of dopamine, the brain chemical that lets you feel pleasure and motivation, and they died because they could not bother to eat enough. You must ensure your desire to complete your goal is strong. Put up pictures that will inspire you in your goal. Tell your friends what you are doing so your pride makes you do what you say you will. Also, it may be helpful to link your efforts with some form of reward. For instance, you might put some cash in a pot every time you complete a task which goes toward a defined treat when you achieve your goal. Tracking your goal can feel good too, marking up your progress.
A tip for getting the habit underway is to find the right cue in the day to do it. If you link it to an existing habit that can help. I will go for my run straight after I have my first coffee, or I will write two pages of my book as soon as I sit at my desk. Sure you can just schedule a time but the important thing is that you do not procrastinate. Your cue is your go.
Try increasing friction with bad habits like putting the chocolate biscuits away on the top shelf every time you have one rather than leaving them out and reducing friction when creating good habits like leaving your gym gear on a chair ready to use.
So remember, when pursuing your goals, taking regular easy steps will keep your stress down and allow you to go a long way.