Just wanted to post and offer some encouragement.
My DD was tube-fed for 4.5 years due to a severe oral eating aversion (brought on by high-dose chemo she received as a baby to treat her brain cancer). She *could* eat, but *wouldn't*. Total refusal to put anything in her mouth for a loooooooong time.
We worked with a feeding therapist for many months when she was around 18 months old, and finally the therapist told us that we should just keep food non-stressful, available, and fun, and one day she would let us know when she was ready to eat. She surmised that our DD would probably be around 5 or 6 years old before that happened. That was tough to hear, but also enabled us to just relax and wait for time to take its course with respect to overcoming the oral aversion.
Eventually we came to a place of peace about it and figured that one of two things would happen: 1) she would want to start eating again of her own accord, or 2) she would get old enough and skilled enough to blend her own formula and feed herself! Either way, *we* would eventually be out of the tube-feeding business!
(We did do blenderized, homemade formulas - drastically reduced monthly costs - but a super powerful blender like a VitaMix or BlendTec is a MUST. We threw *everything* in there - whatever we thought a child her age would eat in a day - and fed it to her. It was definitely a daily hassle, and we always kept a back-up supply of canned formula for busy days or traveling, but in the end figured out a way to make it happen most of the time. Your results may vary! Tube-feeding kids is definitely a lot of work!)
Well sure enough, around age 5 she started showing more interest in goldfish crackers and some other "easy to control in the mouth" foods - things that wouldn't sneak down her throat until she was ready for them. We very slowly started offering them more often, and then she slowly started showing interest in broadening her food horizons bit by bit (from crackers to bits of cheese to cereal bars...) Our children's hospital offers a two-week intensive feeding therapy program (outpatient, 3 visits per day to eat meals with the therapist, followed by a team that includes a feeding therapist, dietician, ARNP and social worker). We asked for a referral and got a slot in the program several months later. We spent the intervening time continuing to follow her lead and doing LOTS of positive talk about how she was "learning to eat" and "getting ready to eat and drink everything by mouth." When we started the program, she was really ready and - with only a few hiccups - pretty much went with the program and transitioned to oral eating. Learning to drink enough liquids turned out to be a bigger obstacle for her, but 4 months after starting the program, she is doing just dandy!
It was a great comfort for us to have the support of the team to counsel *us* as we transitioned from relying on tube feeds to meet her nutritional needs to dealing with the terror of the tiny amounts she was taking in by mouth. It was a tough transition, and she definitely lost weight along the way, which was hard for me, but with the encouragement (and watchful eye) of the team, we were able to wait patiently for DD to get better at oral eating and drinking. And I'm happy to say, she's pretty much there!
So - that is our experience. My recommendation then is to wait until your child starts showing interest of his/her own accord, and then proceed slowly. Then get help from a team of eating specialists who are also willing to move at your child's pace (if anything like that is available to you, near you).
Take care and best wishes!